What if a gay man and a lesbian female married each other and had kids? What harm could they cause? Would that be unacceptable?
It wasn't unacceptable at any time prior to, oh, I don't know, maybe 1990, because nobody knew they were gay. Just look at Michele and Maurice Bachmann. As for all of those gay-pretending-to-be-hetero couples, I'm sure the children turned out to be horrific serial murderers, even the adopted ones. But, Hey! At least they didn't grow up with homosexual parents!