I don't think social "stigmas" have anything to do with the lack of a viable male / female role model in the home.I think the stigma is more damaging to the child then the lack of one particular sexed parent.
If the social stigma of having two same sex parents was eliminated, these children would be 'normal.' Society is more damaging then the child's same sex parents I would guess.
Not being female, I could NEVER offer the kind of insight to a daughter that only a mother could, be it about female physiology, emotion, or behaviors. The best that I could do is cite some shit I learned in a book, and give advice from my male perspective....which just might not be good enough.
Likewise, a female can't offer a son the insight he needs as he becomes a man. And as soon as he hits puberty and becomes bigger and stronger than "mommy", she starts looking to HIM for protection, and as a result, both her "control" and "authority" go out the window. Gay couples will be in the same position, and their "children" will also suffer from this lack of insight.
Blaming "society" for the selfish actions of individuals just doesn't cut it. That's like blaming "society" for not allowing somebody to walk around naked.
Regardless, I'd rather see kids adopted out to normal couples, as they seem to do about as well as any other kid raised in any other normal family. IMO, gay "couples" are better suited for raising pets, not children.