My question was removed but I have seen much, much worse.?

I posted a joke the other day. It was MA rated, definitely not R or X rated. It was removed by the moderators! I don't know much about how it works and I am sure there must be too many questions to check all, but why did my slightly ual joke get removed when there are people on here saying they like to molest children, asking for the quickest way to die, talking about beating up sluts etc, etc. and these don't get removed??????????????