My main reason is the fact other dogs fight too! It's just that people think of pitbulls by how they are tough but really that is just and image that gets fit right into your head. In fact the pitbull should be admired by the usa. An example is stubby the pitbull. He served the USA and has become an hero on fours. He is admired by many and saved lots of lives.
The fact pitbulls have to be put into categories like vicious by birth is not very well justified. One main reason why this happens is over reporting.