Why are movies generally so retarded?

Movies tend to suck for reasons best explained by Ubarose, and also there is Sturgeon's Law.

They kind of have to be somewhat "retarded." If a movie was totally logical and realistic, it'd be boring as hell. I know I wouldn't want to watch something that made too much sense, but I'm a fan of the tropes, genres, and gimmicks of Hollywood, and I'm not much of a critic.