well...i can't think of one word..but I would say "taken care of improperly."
My parents have a red nosed pitbull and he is the best dog ever!! I really wanted a pitbull actually, but my boyfriend wanted a small dog, so we got Jacoby instead!
I still plan on adopting a pitbull in the future. You just have to make sure you assert yourself as the pack leader so they know who is in charge, and give them the proper exercise! I think those pitbulls who end up biting their owners are not cared for properly and they do not trust and respect their owners.