Whoosh. That's the sound of you completely missing the point. The things you said had nothing to do with the things I said. Period. There was no overlap. I say "Heterosexuals can have children that are genetically the offspring of both parents, homosexuals can't." You say "Homosexuals can do these others things". Yes. They can. And your point is? Heterosexuals can do those things to. If you want to counter my argument that heteros have a single choice more, you need to actually counter it, not ignore.
There's also the possibility down the line of eggs/sperm differentiated from stem-cells. But I guess I just don't see it as a problem, to the point where I didn't even see your caveat "equally parts "theirs"" originally as meaning genetically from both parents. A baby is a baby - most of the similarities come from influences while the kid is raised, not in the womb. I know plenty of people think otherwise, but it doesn't hold up to data.
I do wonder about something though. Say somebody has a religion that holds values that contradict homosexuality, like heavy emphasis on families and Husband and Wife and all that stuff. Their doctrine of dealing with evils of the world is to love them as their own family to slowly improve it through association and example.
Would such a person be homophobic? They are technically anti-gay, but what they would do is exactly the same as if they are pro-gay.
I hate to bring it out kicking in screaming into the open (and I really hope it doesn't cause some big argument), but this is basically Christianity without much apology. The problem is that it rarely works out like that. Namely, Christianity is often followed without regard to its core tenet of love and forgiveness whenever and wherever it's convenient. This is because neither are easy. I have no problems with Christianity as a doctrine, it's actually quite nice, but people take things out of proportion too much. I've never seen a supportive or unrepressive family that was also against their kid's sexual orientation, and I have a lot of friends like this.
For a hypothetical religion that has this and no stigma attached, I guess it could happen. It's just that, by and large, the original reason people have been against alternate sexualities is because they're afraid of some instability or threat they might cause them. Looking at the social background for Judeo-Christian societies, it's pretty obvious that was from a perceived threat to lineage and succession, which in turn was the result of women being unable to hold power or authority over a family. I can't see hypothetical non-Christian religion turning out any differently based on how you've described it. Even if it were matrilineal or both, the emphasis on family would likely attach a stigma to any pairing that didn't produce offspring.