The homosexual genetics inevitably kill themselves off, as you have described.
Leaving only heterosexuals.
(That's what you want, right?)
And if they do not kill themselves off, then there is no threat to the human race.
Because obviously homosexuals can procreate just fine, even if they're not particularly interested in het sex.
What's the issue?
As far as I can tell, using just basic logic, there is none.
You can just sit back and twiddle your thumbs or whatever and not worry about the threat of homosexuals destroying the human race.
Now, as far as "social conditioning" for example where a female is abused by men enough that she no longer feels safe enough to make herself vulnerable in sexual relationships with males and decides instead to build a love bond with another woman, well, what's that have to do with evolution?
Evolution is about natural selection, based on genetics.
Not pure social conditioning.
The woman's genes are still 'straight.'
Again, why bring that up at all?
It seems irrelevant to your case.
I'm not seeing a lot of "logic" here yet.
Just fear of Other.