Any dog can snap. The likelyhood of a chihuahua mauling a mailman is a lot less likely than a German Sheppard, but I'll bet my lunch money more people get bit by a dog that weighs less than 15 pounds than bully dogs all day. Pit bulls and bully breeds are infinitely more powerful than ankle biters, but so are akitas, retrievers and irish wolfhounds. The same reason if I get in a fight with someone, I would probably inflict more damage than my son.
I am by no means defending morons who raise dogs for amusement or incorrect reasons, but a pure bred bully breed, bred in a loving home and with proper training is no more dangerous than a yorkie or bichon frize. They are definitely capable of much more damage, but are not more likely to attack humans than any other breed.
Talking someone who has never owned or known a properly trained bully breed dog is like talking to a brick wall. They have their perception of the risks and dangers of said breed based on the bad story they read in the paper or saw on the news. Which seems to be the only breed that makes the news for dog attacks anymore. Even if the dog is an unkown breed, the media will report it as a pit bull despite the fact it may be a lab mixed with a bulldog.
