Why do people seem to like the mean people at school?

People seem to like mean people because their are popular which if you know if someone is mean to you you shouldnt hang out with them, you should just kick them to the curve, and if they have an attitude about it so what just tell them to get over it and you should find new friends, and if you are seeing people that are getting mistreated by someone and they are still hanging out with them they are just being followers.