I don't think HN is humourless, it's just that it's only tolerated if (a) you have something insightful to say anyway and only use humour to spice it up and (b)

I don't think HN is humourless, it's just that it's only tolerated if (a) you have something insightful to say anyway and only use humour to spice it up and (b) your joke is subtle and clever.