Why do Marilyn Manson fans get so defensive?

OK, by no means am i a Marilyn Manson fan. But it's like all the Marilyn Manson fans i DO meet get so defensive when I say i don't really like his music. Can i not speak my own opinion? They get up in my face and say things like "Shut up, you don't know anything about good music." Good Lord people, what's the big deal? I happen to listen to music that happens to be more uplifting. I mean just because music so happens to be cheery and not dark and twisted does not mean it's not good music. Take the Beatles for example, their music is HIGHLY successful and by no means dark and twisted. Manson seems to try and crush people and put people down with his music whereas the Beatles, for example just wanna have fun wit their music. But ANYWAY, why do people get so defensive when you express your opinions on things like this.