Most Helpful Guy
You are simply only noticing the relationships where girls date the asshat guys. There are girls who will give a nice guy a shot. I found one. To answer your question, these girls usually are immature emotionally. They will form an attatchment early on when the guy seems to be great, then the dude reveals the asshat side but the girl still has that attachment and might think she can change his ways. Stop focusing on these girls bad choices and move on looking for a girl who is emotionally mature.