They happen to be control freaks that use women for their bodies or they just plain enjoy manipulating women. I don't really know why. I mean, it could be family issues that have influenced them negatively and somehow taught them or they automatically recovered from that by thinking that it is okay to use women. Or it could just be that the crowd that they hang out with influences them to be negative and demeaning towards women.
I want to know the same about men. I was a good girlfriend and never cheated on my ex. Yet he still dumped me out of the blue by text. For no reason. Saying he should've dumped me a long time ago. Try working that out.
People decide how they let other people treat them. When you get some of these girls who don't respect their own boundaries and standards, then it's no wonder bad stuff happens. A guy is certainly not going to mind if a girl is throwing herself at him. I'm not saying it's all the girl's fault, but if she doesn't demand respect then guess what? She's not going to get it unless the guy has some sense.