I don't know why some groups don't accept controversial stamps. It's completely ridiculous, when people defend themselves from everything that is not sweet, cute, good and true They don't want to see opinions about religion, sex, politics etc. what is idiotic. Why, people, why?!
I think it's 'cause people always want to think that they're right on those topics, and don't really care what others think.....or something...(I would also consider music to be controversial in a way)