This is a serious question. Amoraim seem to be ok with jokes, but Tanach is not so much. Despite some examples of irony here and there, most of it comes from people, not from Hashem. Maybe given the pathos of communications between Hashem and people, humour is just not appropriate for that moment? Imagine, a navi who is preparing for the occasion and learning a bunch of Heavenly jokes instead?! Maybe Yona’s kikayon counts as a practical joke, we are just not used to read it like that.
