What girls look for

if girl wants a guy with a good personality, intellectual, blah, blah....then why, do girls go for the bad boys? a lot of the girls i know, said if they werent with their boyfriends, they'd be going out with me (i think they are just being nice)....their bf are complete dicks, treat them like sh!t, and all the other things that are associated with being a cock, why do the girls put up with it? i mean if you girls are truly looking for the nice guy(not saying most of you are), why go out with a guy that treats you like crap?