Pedophilia is a sexual attraction to children. To be a pedo you do not have to ever touch a child in your life. But to be attracted to children, you can't exactly help that. Think about it. Can you just change, in a second, what type of people you're attracted to? No. You can't. Same thing.
CHILD MOLESTORS, on the other hand, HAVE molested children before. Which is a crime. Attraction, thoughts, and other such mental activity is not illegal, hurts no one, and is not something to physically harm someone over. It would be like hurting a gay person JUST because they LIKE the same sex.