Is being polite dead?

Why is it that people think, when they are mean to other people, that they will succeed. I was speaking with a c0-worker who happened to be an "extra" for movies, and his friend was an aspiring screenwriter/director that used him for movies. And my co-workers comment was that his screenwriter friend will be successful because he is an asshole. I mean come on, do you really have to act like a pompous jerk to be accepted into society or the Hollywood world. Isn't a nice humble approach better? Whatever happened to being nice, and doing unto others as they do unto you?