This is obvious to most people.
But these truths do not "fit" with feminist ideas of "constructed gender".
What do two gay dads know about what it is to be a woman? I don't care if they are effeminate, they're not women. They don't feel like women. They don't hurt like women or react like women.
When you don't have a parent of one sex living in your household, that's an emotional handicap. It doesn't mean you can't get past it. But it's still a handicap.
Kids need a mom and a dad. Minimum!