"Punching," in this context, is a term used in humor to refer to "making someone the subject of a joke." Are you trying to suggest that people shouldn't make jokes about people?
Besides, the sub you're complaining about exists to make fun of a specific attitude unique to people with privilege: ignoring cultural nuance and context behind a joke and overreacting when harmless stereotypes about their group come up. For example, a (white) person hearing someone joke about "white folk can't dance" and starting to throw around racial slurs and all sorts of really damaging stereotypes in reaction. Or someone seeing a forum dedicated to pointing out how sensitive people can be about their social privilege, and suggesting that nobody be allowed to make jokes about other people in reaction.