It's like asking - is it true that black people have statistically larger lips than people of other colours - then is that really racist? I don't think it is. But if you take the answer to that question,and somehow infer from it that because of it your "race" is better than others, then it only means that you are racist,not the question.
My point is - scientists need different kind of statistics to understand how the world works. If they ask if a child raised by two gay people is more likely to have problems with its own sexuality, then I don't see that as homophobic or aggressive - it's not personal after all.
The problem is that these sorts of questions are often the precursor to banning unconventional families until someone proves that no harm is done. That sort of thinking is harmful, but I don't think asking the questions is harmful.
Likewise with the race question: if a poster had asked "does the white child raised by black parents identify more strongly with black culture than other white children?" that might be a legitimate sociological question, but the implication that that's a problem is what makes the question problematic.
(kidding!)
I am sorry if you felt offended by my question, but you should realized that in some country (mine as example) being gay, gay marriage, gay adopting kids, are big issues, and there is a lot of questioning and discussion about.
If we are going to be open-mindedly curious, then let's ask questions like what is the basis for imagining that being gay is a choice?
You may not be aware of this, but this question will likely get you downvoted as it will be perceived as homophobia (or at least heteronormativity).