Pits are so eager to please, they will do anything to please their owners. If a Pit is mauling people, it has been trained to do so. Pits are normally animal aggressive, people friendly. We should also outlaw cars, because cars kill more people than Pits do.
The comparison of cars and pitbulls only hurts the pitbull argument IMO.
There are more pros than cons of cars. There are not really any alternatives to cars, either. That's why we should have them.
The same could not be said for pitbulls. The cons outweighs the pros, and there are several breeds that could be offered instead, such as a Golden Retriever.
Pitbulls are very seldom used for anything else but companionship, ie they're a luxury item. There are other breeds that are better suited for duties such as supporting blind people, searching for narcs, herding sheeps, et al.
-Hedge