How does a nice guy end up attracting women that are damaged goods?

Earlier I asked a question about why women find the "bad boys" attractive. What I meant by that is the guys are the guys I call "vampires" because on the outside they're charming and seductive. On the inside they are incapable of empathy, remorse, or any humanistic qualities. Why does it seem that the women who go after the nice guys are the ones who either have kids with the "bad boys;" they're damaged goods; or they end up with all sorts of problems. Why do I as a nice guy who tells it like it is end up with the ones who seem to be over the curve? Do they come after me to make amends for dating to the wrong guy? Is it to ameliorate all the psychological damage they experienced? Or is it because they wished they'd dated the nice guy from the beginning?