Well, I am of the mind that both "nature" and "nurture" are involved. You're going to be predisposed towards some things, while others you pick up from your environment.
That being said... being the kind of person I am (edit: the kind who needs the millions of details before deciding), I don't think we can say what kind of person he'd be exactly without knowing the parenting style, the values taught, etc.
I don't think being adopted by a gay couple would guarantee that he'd be open-minded about "da homos," though. If he had parents that didn't tolerate laziness (not just strict Asian parents), he could certainly be more productive. However, all of them would have to have gotten CWC the care and help he needed at a young age or we could wind up with a similar result or something worse.