I wouldn't care much either way. Blood-relation is meaningless in-and-of-itself. My parents are my parents because they raised me, took care of me, and were generally good to me. Not because they share some genes with me. If any blood-relation happened to be a really bad person, I would have no problem pushing them out of my life as much as possible.

For the same reason, I wouldn't give a crap if, in the adoption scenario, my biological parents turned out to be horrible people. Because they wouldn't really be my parents.