Outrageous is NOT the right word here. Outrageous implies a moral baseline or judgement from a moral authority. I suggested their lyrics are provocative, that is thought provoking. When I sent my 20 yo daughter the link for "An American Prayer", I told her to be mindful, it's vulgar but required listening to understand the Left in our society.
In “The End” he speaks of screwing his mother before he kills her, and after he killed his father.