I suppose if you're butt-ugly, you don't really have a choice of choosing to be a nice guy or not. If you're nice, girls will tolerate you, and put you in the friend boat. If you're not, well, say hello to hikki life.
Also, there's a difference between personality, and just being plain old nice. The "nice guys" that type these whinge posts are often the ones who expect to get sex/affection by just simply being nice to a girl. Anyone can be nice. What a girl wants is personality. Personality in the sense that one is sure of who they are, and possesses self confidence. Which is what most self titled "nice guys" lack.
Assholes/egotistical/jerk-ass guys often have the two above things.