I agree with what you said, and it is borne out very well by my experience of gay persons. As for gwern's comment, the silliness is to think that evolution has enough selective power to completely remove that sort of thing. In fact, it would be far easier for evolution to remove a gay gene than for it to prevent things that happen through accidental social circumstances.
Consider this: I am over 40, I do not have children and have never had sex, and I have no intention to do so. Shouldn't evolution have completely removed the possibility of people like me? I am not even helping other people raise children. I live alone, and consume my own resources.
The answer is that if "people like me" came about because of a specific gene, evolution would indeed have removed the possibility. As it is, it comes about through a vast collection of accidental and social facts, and the most evolution can do is make it rare, which it does. The same is true of homosexuality.
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