It's certainly a more likely fate if they have to go through foster care.
Anyway, as to gays adopting? I don't know, honestly. On one hand, all research suggests that gays are perfectly capable parents, certainly better than foster care. On the other hand, you do have the ethical issue of children having to put up with teasing from classmates for having gay parents.
Yes, kids always tease, but kids with gay parents will certainly receive more serious teasing, since many of the kids will have redneck parents who will have given them the idea that making fun of them is the right thing to do (i.e., "Daddy told me that your parents are going to Hell!"). Teasing kids with gay parents is going to be much more venomous than teasing kids because they wear glasses.
This issue is nothing new; it happened in the civil rights movement when integration first started. We forced the black children of America to go to the frontlines of the battle for equal rights when we put them into formerly all-white schools, and they had to endure the harassment and the insults.
It's honestly a really morally ambiguous issue, and I can't say that I know for sure what the answer to it is. In the end, though, I'd say that enduring the teasing is a lot better than having to go through foster care, and in the long run, it will provide children with parents that are respected by society in the future.