This is why I don't talk politics in polite company -- most people aren't polite. I said something not particularly controversial and within seconds, I'm called a bigot. That's not an argument. That's name-calling. And it's not true.
Though there is very limited research on the topic of same sex parenting, what research exists suggests that no, two same sex parents are not as good as two parents of the opposite sex. You'll note I never mentioned biological parents, because the statistics suggest that adopted children in two parent (of the opposite gender) homes do best of all.
Like I said, not stuff I typically talk about. I just read the research and listen. Again, I'm not suggesting we make decisions based on what the research suggests, I'm simply saying we shouldn't lie about it. And now, birther pit, I'm out. Flame away, children.
...maybe they're not as good cause they can't marry?
who knows. This is not, and will never be, a scientific argument to favor both sides IMO. Just like you cannot prove or disprove the existence of God scientifically, neither can you prove who is the better parents. For to do so would require defining what is a "good" parent => which is obviously subjective and contingent upon societal morals and beliefs of what is good => which are mostly rooted in religion.
And don't be confused by the word religion. we all have a religion. for those of you stating you don't care what others do as long as it does not effect you - guess what, that is a belief that plays into how you view the world and conduct yourself (i.e. a religion). It's just a word, right? Also, saying you don't care what other people do as long as it does not impact you is technically a flawed logic - not to mention lazy. It implies that only what benefits you or your interests is right and anything denying you from your interests is wrong. this is pretty standard existential fallacy - as it is not scalable to everyone.