Anybody inclined to criticize the song for being simple... go try Paperback Writer by the Beatles (2 chords and an adorable riff). Simple is elegance in the right hands... Rammstein has the right hands. ;)
I think it's the difference between 'minimal' and 'simple'. Simple implies easy, but it's hard to make something as minimal as possible while having it remain interesting and functional at the same time. (Same as in design: That's also why some websites and apps LOOK very clean and simple, but when you use them, you find that it doesn't work as expected, or are just not useful anymore.) It takes a lot of skill to write such an interesting and moving song with such 'simple' chords (and minimal drums too, by the way). AND it's difficult to keep writing songs like this and simultaneously avoid having them sound the same.
I was screwing around with the way my guitar was tuned cuz it just wouldent sound right but its because u shouldent use the E string, it makes it to heavy.