"Humour is a way of coping" - true - but that axiom is also the default rational for every supposedly-humorous breach of taste, civility, respect, and good manners. Look at how many times it has come up on this thread alone - now recall all the other threads in which has it has appeared, over and over again.

Not every sick joke is a "way of coping" - sometimes, to paraphrase Freud, a sick joke is just a sick joke.