Art and the act of censorship

i just got a note saying my picture iLust needs a mature content warning and too right its a naked woman with an iPod for a vagina they (deviantART) changed it for me and they have every right too
but when i was changing iLust nano another piece of art which is an actual closer up of the vagina/iPod i noticed that one of the maturity warnings is nudity .... i can under stand the other warnings sexual themes violence strong language but nudity? really? this is an art web site life modelling and modelling nude have gone hand in hand with art since cave men drew on walls
i just wondered why that’s so why nudity in art is censurable ?
i don't seem to be able to understand why the naked body is so offensive I can see how bad language violence and some and I repeat some acts of sex (rape child molestation etc ) can be offensive on the most part the human body is a beautiful machine
If I felt more beautiful about myself I would wear less clothes and share my beauty as much as I could with out being vein and by that I mean I would donate my time to a art class or something I wouldn’t just walk around top less striking a pose
Arts censorship is something that really gets me hot under the collar I can’t stand to see art censored because art is a pure form expression and how can expression be bad?

the link to my deviantART page is on the side bar