A common silencing tactic is to claim (post hoc) that oppressive comments are "only jokes" or that the people affected by them should "get a sense of humor". This silencing tactic reflects an expectation that marginalized people should laugh at jokes that are at their own expense. It also reflects an assumption that if we avoided jokes that hurt people, we would be humorless -- in other words, that all humor necessarily involves the reinforcement of existing power dynamics.
"It was just a joke" is almost always used to defend alleged humor that "punches down" (enforces existing power dynamics); often, the same people who demand more of a sense of humor from others become very humorless when faces with humor that punches up (challenges existing power dynamics).
