I agree that they can be a dangerous breed and also agree that taking the time to find a reputable breeder with dogs of even temperament and sound disposition are key factors. And one of the main problems now with Pits is there are a lot idiot breeders that just want to make a quick buck, and have no intention of maintaining the normally good nature of these dogs.
But with that said I don't believe that they are inherently more aggressive towards humans then most protection dogs. In fact in my experience they are far less aggressive than most P.D.'s but I do not dispute that these dogs can and have hurt/killed people.
Are they more aggressive towards other dogs than any other breed? Again I don't believe this to be the case either. Can you really say they are more dog aggressive than an alaskan malamute, dogo canario, tosu inu.........and I am sure I could list a half dozen more?
Again, you could wipe the pit bull breed out of existence and there would be a bunch of breeds just waiting to take its place. And as you said "there are many more breeds including GSD's that physically posses the ability to be MORE dangerous than Pits". Now all they need is to be bred and owned by the same unscrupulous people that destroyed the pit bulls reputation.
Its really just the beginning of the end. One day owning any potentially aggressive dog will probably be against the law. Governments don't seem to want to solve the really problem.