Humour is a Delivery System for Content
Saying that someone is humourless because they don’t laugh at your insulting sarcasm is like telling someone who is rejecting unwanted sexual advances that they’re frigid.
Humour is form, and as such, it’s a delivery system for any content, be it intended to attack or to support, to divide or to connect, to establish one’s own status or to be of service, to incite hate and fear or to inform and educate.