The inherient problem is that any dog can be vicious, and any dog can be sweet. Small dogs are the most notorious for being bad for children and aggressive, they are just too small to do any real damage. I pitt, in the right hands, can and will be the sweetest dog in the world. I have a boxer mix (similar family as pitts), and he has a lot of the same features. A lot of people when they look at him think he is mean, but he does nothing but wag his tail and lick.
The reason that pitt bulls are so feared is because they are the most likely, if there is going to be one, for a dog attack. This is not to say it is the pitt bull's fault. This is far from true, the fault lies in the owners. But the owners who raise the pitt bull to either be aggressive or able to be triggered are the same ones who choose a dog for the traits a pitt has. This dog has a massive bite capacity. I remember reading it is proportional to an alligator bit (size of jaw to size of jaw). They are an extremely muscular and athletic breed. They are also small enough to keep in more confined areas (a rotweiler is very big...). The owner selects a pitt bull for his characteristics, and then sets the dog up for disaster.
This will not change until there is better screening on the breeding and selling of pitt bulls. This is extremely hard to do, and thus why it has not happened. The image also needs to be spread of how sweet they can be, and not just how vicious. Until it is not cool to have a hard a** dog which people raise them that way, pitt bulls are going to have this image. And it is a shame, because they are wonderful, loyal, and sweet pets.