To a lesser extent, I've seen something similar with anosmia. There's no public outcry against it, but there's also very little public awareness of it. This is where the internet comes in useful, since you can find other people from a niche group, and it's quite a relief to realise that you're not alone.
Having said that, I can't help nitpicking the premise of this fantasy world. I think it would be a good basis for an SF story, but as it stands there are lots of unanswered questions. Most importantly, why hasn't the human race become extinct? Nowadays we have the technology to get round this (e.g. artificial insemination), but that's a relatively recent development, so what happened 1000 years ago? The novel "Ethan of Athos" works on this premise, by assuming that a group of men founded a colony on a new planet explicitly to get away from women, but that's set in the future, and it's significantly different to our world.
There are some lizards which reproduce by parthenogenesis: this basically means that the females clone themselves by asexual reproduction, and they don't need males at all. Meanwhile, honeybees are a haplodiploid species: they don't have a Y chromosome, and male bees come from unfertilised eggs. It's plausible that a species could combine these traits, producing both male and female offspring without the need for sexual intercourse. However, at that point you've made some pretty major changes to human biology, and that would surely affect their social structure, so it's not really a fair mirror of our world.
A common objection to homosexuality seems to be that it's "unnatural". I've heard similar arguments in the context of being vegetarian (i.e. that eating meat is natural), and I'm not convinced; surely either everything we do is natural by definition (since humans are part of nature) or we should adopt a "back to the trees!" mentality. However, if this other world has similar biology to our own then it would be hard to describe heterosexuals as unnatural, so I'd expect the criticism to be something like "We've evolved beyond that". Would the inhabitants of this world be sneering at their grandparents?
It seems unlikely that people would sing "I'm gay! I'm gay!", in the same way that people don't sing "I'm straight! I'm straight!" in our world. I'd expect it to be more like "When a man loves a man..."
The story refers to "breeder babies": in this hypothetical world, is it ok to be a pregnant woman if you're a lesbian? How is that person any less a "breeder"? Alternately, if there's massive hostility towards children in general, wouldn't that have wider implications, e.g. a shrinking population?
Still, leaving that aside, is this behaviour a valid reflection of the real world? It's hard for me to say, since I'm not gay, so I haven't had the relevant experiences. Still, I'm a bit dubious about it. The equivalent would be a closet homosexual who doesn't want to reveal his/her real lover, so as far as everyone else is concerned he/she is a single heterosexual. That cover story is an accurate description of me, so presumably I should encounter some of the same situations as this hypothetical person.
For instance, "you panic when people attempt to fix you up with their brother or sister". (I'm making small changes to the text/formatting in these quotes, for clarity.) I don't think anyone's ever tried to fix me up with their sister, or any other female acquaintance for that matter. I'm not complaining, and this may just be specific to me, but do other people have to fend off blind dates on a daily basis? Or putting it another way, do you frequently try to play matchmaker for your single friends?
The story also describes a situation where you have a "flatmate" who is actually your secret lover; when they are in an accident, and get rushed to hospital, you only find out about it later. So, you go to visit them, but you have to restrain yourself to avoid blowing your cover. "Do you go into the intensive-care unit, or do you sit outside and wait?"
When I first moved to London, I shared a two bedroom flat with a male friend from Durham. We lived together for a year, then a few months later I moved into a different two bedroom maisonette with another male friend from Durham, and we lived together for the following four years. If either of them had been taken to hospital with serious injuries then of course I would have visited them; that's what friends do, and I'm sure they'd have done the same for me. I wouldn't have worried about people thinking we were gay, although admittedly I wouldn't have been kissing my flatmates. I can understand why people would get cautious after a lifetime of bad experiences, but I also think it's possible to cross the line into paranoia, where the limits on your behaviour are self-imposed rather than coming from the people around you.
Some people have asked me whether I'm gay over the years; that's out of general interest rather than as a pickup line (e.g. from the girls I shared a house with in Oxfordshire). On balance, I take that as a compliment, since it implies that they were surprised I didn't have a girlfriend. So, even when people thought that I was gay, I didn't have to deal with any abuse; I realise that not everyone is quite so tolerant, but I also don't think it's a universal problem.
The story also asks "What if every book you ever read, every movie you ever saw, every billboard you ever passed featured the beauty and joy of gay love?" This implies that every book/movie/billboard in our world features the beauty and joy of heterosexual love. Really? All of them? I understand hyperbole, so if the author really means "The vast majority, with a tiny proportion of exceptions" then that's fair enough. For films, he may have a point, depending on how you define it; even where a love story isn't the main plot, it tends to appear somewhere. For books, I'm a lot more dubious; I've read plenty of reference books which don't mention love at all. Even if you restrict it to novels, I still think there are plenty of exceptions. For instance, I grew up reading the "Adventure" series (by Willard Price), about two brothers who travel the world capturing animals for zoos, and I don't remember any romances. Similarly, the "Jennings" series (by Anthony Buckeridge) are set in a boarding school for boys, and the main characters are too young to have any interest in girls. So, I suspect that what you encounter depends on what you choose to read. Still, I've only read a small proportion of the books out there, so my experiences may be unrepresentative.
As for billboards, this is where I can hopefully be a bit more objective, since I will see the same adverts as everyone else in the same place, so it's determined by geography rather than personal preference. As an exercise, yesterday I took photos of all the billboards that I passed on my way to work, between Willesden Junction station and Central Middlesex Hospital.
Here are the pictures; sorry that some of them are a bit crooked. Some of the adverts are duplicates, but each picture is of a different physical billboard.
So, that's 18 companies, with 20 distinct adverts, spread across 28 billboards.
L'Oréal have three billboards (two different posters), and I vaguely recognise the women as celebrities. I'm guessing that they are well known as having children, so this probably counts as celebrating heterosexual love (if I err on the side of sensitivity).
The apprenticeship poster just shows a hand, so I'd say that's neutral. (It might be significant that it shows a white hand, but that's a separate issue and I don't want to get sidetracked into that here.)
Premier Inn are two different posters, which just include text, and they look neutral to me.
Churchill have one poster, showing their dog mascot and some text, so that looks neutral too.
The "American Gangster" DVD shows two men; I haven't seen the film, so I don't know what their relationship is, and there's no indication of them having wives/girlfriends on the poster, so I'll rate that as neutral.
Halifax have two posters, showing a woman in boxing gloves; again, there's no indication of her sexual preference, so I'll treat that advert as neutral too.
Nokia have two posters, which show three people in a triangle around a mobile phone. It could be a subtle hint that they're in a bisexual polyamorous triad, but I doubt it, so I rate this as neutral.
Suzuki have two posters, showing a woman (presumably) in high heels, dragging some toilet paper along the floor behind her. There might be an argument for saying that high heels are a tool of the Patriarchy, and so implicitly this woman is living in a society dominated by heterosexual men; ditto for the woman wearing make-up in the Halifax advert. However, I'm rating this as neutral.
Audi have two adverts, showing a picture of a car (no driver visible) and some text, so I rate them as neutral.
Similarly, Transport for London have an advert showing a car and some text, so I rate them as neutral too.
BT have two adverts showing a phone and some text, talking about free weekend calls. I rate those as neutral.
Yellow Pages have three adverts showing their phone number, and saying that all their call centres are based in the UK. It might be parochial (although I've had enough hassle with overseas call centres to support the policy), but I don't think it's relevant to homosexuality, so I'll rate this as neutral.
Britannia have an advert that just contains text, although the corner is flipped down; unless there's something very unusual in that hidden corner, I'll rate this as neutral.
Mercedes-Benz have one advert for their Viano car, which just seems to be a picture of the car with some text above. The bottom half of the poster is obscured by flyposted adverts for musical events, but I don't think they count as billboard adverts so I'm ignoring them and I rate this as neutral.
Lexus also have an advert with a picture of a car and some text, so that looks neutral to me.
MacMillan Cancer Support have one advert, showing two people in silhoette. I'd guess that they're both male, but the implication is that they're strangers (one person who needs support and one person to support them) rather than lovers, so I'll rate this as neutral.
The film "Horton Hears a Who!" has one advert. I'm not familiar with the story (Dr Seuss seems to be more of an American thing), but I can't see any obvious signs of heterosexual love. I'm guessing that the two characters on the right are parent and child (based on the height difference), but I'm not sure about their gender. So, I'll rate this as neutral too.
Becks have one advert, showing a man pushing a barrel and a pint of beer. That looks neutral to me.
Overall, that means that only L'Oréal come close to meeting the description. That's 1 company out of 18 (6%), or 3 pictures out of 28 (11%), but it's a significant minority either way.
As I mentioned before, I'm not in favour of any kind of quota system for demographic groups. On the other hand, I don't think that the adverts are dramatically skewed towards heterosexuals, so it's a bit of a moot point. Still, maybe I'm wrong, and I'm just blinded by my own Privilege. I also recognise that this is a ridiculously small sample set for statistical analysis, and that things may be different eleswhere. So, what do the rest of you think?
Of the 18 companies above, how many have billboards featuring the beauty and joy of heterosexual love?
With billboards in general, how many fit that description?
Have the proportions changed much in the last 10 years?
I don't mean to dismiss the original story, and I agree with tackling injustice where you encounter it, but I think there's a risk of damaging your credibility if you exaggerate problems.