Why do so many people hate RAP MUSIC?

Why do so many people have only negative things to say about rap music. Ive heard things like its stupid, pointless, tasteless, or even there is no art in it. I mean if it really wa all of this why ha it lasted this long. Then people say its dying..NO its going through a transformation. It might not be a good tranformation or one that everyone will like but that the way the world goes. Also not everyone who raps in non educated or stupid. The way they talk is often a cause of their enviroment not jst because the want to sound illiterate. Everyone expresses themselves in different ways and that is there outlet. I have alot more to say but willstop here.