Another pit bull owner, Greta Godoy, agreed with Rosario. "It all has to do with how you teach them, how you nurture them,'' she said. "If you do abuse them they will become very aggressive.''
That's the problem. It's usually thugs and idiots who buy these dogs. These dogs are attractive mostly to idiots who will not be responsible owners. Irresponsible owner + Pit Bull = killing machine.
You hit upon the reason why banning them won't solve the problem: These same people will just go buy rotweilers, and neglect and abuse them the same ways.