Everybody has a sense of humor; it’s just valuable to have places where earnest discussion can avoid being swamped by it. HN’s guidelines communicate that it’s

Everybody has a sense of humor; it’s just valuable to have places where earnest discussion can avoid being swamped by it. HN’s guidelines communicate that it’s meant to be one of those places, and so people who appreciate that may downvote, flag, or chastise things even when they do find them funny.