Well see, Bruce Banner had the same type of childhood; abusive as fuck dad and all that. And while he does have his own issues, at least Bruce is trying to do the right thing, trying to rein in the Hulk and get rid of him (or at least redirect him into a force of good).

So no, having a crappy childhood is not a "get out of responsibility for your actions: free card. I can name at least five super heroes who have had childhoods just as crappy who didn't turn bad.