There really are some girls who gravitate towards charismatic jerks. Not all girls, certainly, but definitely some do.

(The why of that is obviously another complex question... Are they social submissives who have trouble believing that they deserve better? Did they have charismatic asshole fathers? Do they just have really terrible taste? I imagine their reasons vary quite a bit.)

I personally take amused umbrage at "nice guys finish last", since I married a nice guy, and prefer not to be considered a consolation prize. ;)