Anyone who ‘only’ uses a breed's reputation to say that it should be banned is only using that reputation as excuse for a poor understanding of animal behavior. Most dogs, regardless of breed will bite/attack if they are raised in a home that provides poor socialization and/or lack of leadership or if they feel threatened.
I think that certain people would not provide the proper home for such a breed, and should therefore, not own one. Those who want the animal to supplement their own aggression/power should think again, and buy a goldfish. Educate yourself about the breed you want to own, and then put the work into the dog to have it become a loved and valued member of your family. Like children, dogs know what they are taught, or in most instances, not taught. Irresonsible breeding can be as much to blame as irresponsible animal training. A conscious pet owner not only researches the breeds characteristics, but also the breeders philosophy and reputation.
I think if somebody is attacked by a dog it is often their fault or the dogs owner. If the owner let's the dog loose, takes a violent dog out in public without leash or muzzle, or keeps it in a poorly contained area then it's their fault if the dog harms someone. However if you go to someones house and let your children run up to a dog while it's eating, or let your kid jump up and down on a dog while it's sleeping you're setting yourself up for disaster. I believe it is my responsibility first and foremost to make sure my child is safe, just like I buckle him into his carseat not because i'm a bad driver, but because I don't know who out there is driving recklessly.
I don't think that a ban for certain breeds is the “perfect” solution, because every dog can “flip out” when it feels threatened or cornered. Some people are attracted to vicious looking dogs and buy, train and/or breed them to encourage that behaviour. It's the people who raise and train the dogs that are largely responsible for their behaviour. Lack of training is also often a factor. Dogs, by their very nature, are predators. They practise that behaviour in play as puppies. If they are not taught otherwise, they grow into 'big puppies' and continue the behviour as well as trying to be 'head dog'. Then, it's often too late to retrain them. And it's not their fault for acting on their instincts.