Pit Bulls: Characteristic or actual breed?

Now, everyone loves to give the pit bull bad reputations and talk s**t about the Breed. But, when given a test, about 80% of people can't pick out the actual PIT BULL BREED. There are certain characteristics that most people will look at in a dog and automatically say it is a pit bull. Some dogs that get the "pit bull" bad rep: American Bulldog, Boxer, Bullmastiff, English Bulldog, Lab Mixes, Some Mastiff breeds, and even Rhodesian Ridgebacks. But most of all the American Staffordshire terrier. I was just kind of wondering....Why? Why can't people get over themselves that most "pit bulls" as they say are not even part of the actual pit bull breed? Why do people clify so many dogs into this "vicious" group of dogs? So I wanna know what you think: Is the American Pit Bull Terrier seen more as an actual breed or just a characteristic?