Perry why are you so hung up about being the "bad guy" if you have to dump someone? When someone enters into a relationship, and all intentions are made clear from the beginning, then being dumped is the chance one takes. It certainly doesn't make you a villian.
I was the dumper in alot of my past relationships. I don't feel lasting guilt about it beyond the initial remorse. But why was I the dumper the majority of the time? Most likely I was picking the wrong people for the wrong reasons to begin with.
Some people, like the women you describe, would rather stay in a bad relationship than be dumped. It doesn't really matter if it's a FWB relationship or a long term one. People generally don't take rejection well. Females and males alike.
“Inside every cynical person, there is a disappointed idealist”--George Carlin