I don't think that is true at all. I find it interesting that the religious angle is the only explanation for people being uncomfortable with homosexuality.
That doesn't mean you hate or even dislike someone who is. I honestly get weirded out when I see it, though to be fair, I don't really want to watch someone else make out in my face regardless of sexual orientation unless I'm trying to prime myself for amorous activity. I don't cast aspersions on people who (for whatever reason) feel/act in a way natural to them, and I would never advocate treating someone as less of a person solely based on sexuality. But trying to tell me I'm somehow backwards (I don't think you are saying this, I am being general) because I don't love to see it is a bit ironic, imo.
So many things we do are tied to natural evolutionary viable actions/ behaviors. A general revulsion makes sense if you want keep a species in existence. Sex and relationships are so controversial because they are based in mating ritual/ child rearing, so a natural tendency to reject actions out of line with that makes logical sense.
It's the same reason violence rates so low on the controversy scale. It's literally how we have survived threats to our lives through all of history. It's a massive part of how to survive and even thrive (in some contexts), and has been forefront to humanity for all it's existence (like sex). On the other hand, ironically, First-world nation populations largely have zero experience with that kind of real violence, so it's not very relatable, making it easier to take lightly. Granted, I HAVE personally seen that kind of violence, and it doesn't bother me in games (see reason 1).
That's MY two cents, anyway. I just know that calling people evil or wrong for having a natural reaction to an evolutionarily non-viable action is as wrong as hating people who can't help how they feel about people of the same sex. More understanding is needed.
I think there's wayyy too much evidence at this point proving it's predominantly psychological. Even if you pretend that the majority of culture, religion, programming and education hasn't been a form of aversion therapy for the past few thousand years, there are too many examples where it's not a biological emperitive to be psychological repulsion.
To begin with, there would be more obvious expressions in the animal kingdom where gay creatures are shunned by packs, they'd be killed, eaten and abused.
Another is in more progressive countries where it's openly 'normalised', the average on the Kinsey scale is gayer/bi-sexualer. Not only that, but the average on the Kinsey scale has been getting gayer for the past 50 years, and still is. Countries that have a higher average have fewer hate crimes, lower suicide rates, and a bunch of other crap.
There's also the Klein metric which is more accurate, but hasn't been around as long... But what does that have to do with it?
I guess I'm saying that there's 50 years of evidence that shows that people are getting gayer, or at least less straight, and that's not enough time for a massive biological shift, but there is enough evidence to prove that it's easy to disgust people with psychological cues. Feeling a discomfort, or awkwardness is generally associated with ingrained aversion therapy, and most people don't even notice it when it's going on around them.
The first time I fingered a girl, I literally threw up. After trying it a few times, I was like, "Oh, ok... It's like herd testing cattle... Can I get my arm in there." I'm not attracted to it, and I doubt I could ever get a boner when a vagina is too close to me, but it doesn't repulse me now. I just can't see them as sexual...
If you get exposed to something enough it would normalise it for you. If you had to watch gay porn each day for some reason, eventually you'd not even bat an eyelid. If it was biological, it wouldn't be that easy to get rid of.
Not to say that it couldn't ever possibly be a component, but experts in socio-bioligy largely disagree with you.
For it to be considered logical, there would have to be an adaptive reason for the biological expression, and a beneficial reason for the purpose of breeding. Since the gay subject wouldn't be considered a threat for the purpose of you producing kids, nor a threat to the kids, it's considered useless.