I wonder if many people who've seen A Serbian Film
all the way to the end have been offended, outside Serbia?
It makes a strong point against actual sadism by countering the villain's belief that only real is good enough by merely existing.
Also as someone who has very lacking knowledge of commonly known history, there was something to be learned in the film and comments around it, if not more than vaguely, so that aspect's not bad either.
Seems like people who don't accept societal allusions in such a grim movie, wouldn't accept the movie in the first place, doubt that does any damage either.