My dog says disliking a dog merely because of his or her genes is breedism! Unfortunately, breed discrimination is rampant and pitbulls are the most common victims.
Just like people, dogs are shaped by their experiences. You can have an aggressive poodle or a passive Rottweiler. It's not all about breed.
Check out these great stories of pit bull heroes. And, remember, don't judge a dog by its breed any more than you'd judge a person by his or her skin color. Discrimination stinks!