Regardless of the fact that it is wrong to discriminate against gay parents, I believe it is wrong and against one's basic dignity to deny information regarding who we are. People have the right to know who their bio parents were, as much as they have a right to a "name" - Yes, you have the right to a name that serves as an identifier of yourself, and you can legally change it - I'm sure 100% of people here have a real life name. My GF started reading books about adoption later to understand the phases she went trough. It's not easy. Hiding things will usually not help. Many kids want to find out who bred them, it's normal. It doesn't mean they will ditch the adoptive parents and go live with their bio parents, they might even hate those people, but curiosity is normal.
Whoever fights monsters should see to it that in the process he does not become a monster. And if you gaze long enough into an abyss, the abyss will gaze back into you