Hello!
I'm glad you brought this up because I have actually owned a pit bull and yes this bad rap is mostly unjustified in my opinion.
Any dog can become dangerous and aggressive towards other people and dogs. Yes, some breeds are more dangerous/powerful than others but most dogs are generally good dogs
Most behaviour problems that people have with their dogs is due to lack of training and propper care on the owners part. Dogs want and need established rules and guidlines and need you to be their pack leader. If this is neglected than of course you will have behaviour problems whether it is a big dog or a small dog. From my own personal experiences small dogs are more aggressive then big ones; they have small dog syndrome and feel the need to compinstate for their small size with attitude
It all has to do with the breed of your dog as well. Some dogs were bred to be more aggressive and for those dogs training and propper supervison and care is so important. I know for pit bulls they were bred to be fighting dogs; they have a natural instict in them to fight. So, because of this behaviour that was bred into them it is important for an owner to be vidgulent and strict about training and make sure your dog is never left unsupervised around other dogs. Again, it is up to the owner to be responsible for the dogs behaviour and actions. Actually, the dog I have now is more aggressive than my pit bull was!
Pit bulls are very smart, affectionate, playful and loyal dogs. They learn quickly and always want to please you. They have such a bad rap because of the irresponsible owners who just get that breed because they think they look mean or think it is cool to own one and then don't realize the training they need to have. They need to be properly trained like any other dog but it is even more important because of their strength and power. A few bad apples ruins the whole bunch! Aslo, I think a lot of people think they are so bad because that is the breed you hear most about in the news. A lot of other breeds of dogs bite people and are aggressive just as much as pit bulls but you never hear about them because it doesn't make good news. You wouldn't care if there was another shitz tzu attack but you would watch and remember if there was a pit bull attack.
Any breed of dog big or small can become aggressive and dangerous without the propper training and care. Even though dogs are part of our families and are like our children they are still animals and have animal instincts so even the nicest dog can snap at you one day.