To put it another way, ask a professional comedian to complete a joke with a punchline. It's very likely that they'll give you a funny surprising answer.
I think the real explanation is that good jokes are actually extremely difficult. I have young children (4 and 6). Even 6 year olds don't understand humour at all. Very similar to LLMs they know the shape of a joke from hearing them before, but they aren't funny in the same way LLM jokes aren't funny.
My 4 year old's favourite joke, that she is very proud of creating is "Why did the sun climb a tree? To get to the sky!" (Still makes me laugh of course.)
2.5 is also one of the few models I've found that will 'play along' with jokes set up in the user prompt. I once asked it what IDE modern necromancers were using since I'd been out of the game for a while, and it played it very straight. Other models felt they had to acknowledge the scenario as fanciful, only engaging with it under an explicit veil of make-believe.
I've been asking this on every AI coding thread. Are there good youtube videos of ppl using AI on complex codebases. I see tons of build tic-tac-to in 5 minutes type videos but not on bigger established codebases.
Law is agreeable hate, in a way. Things that gets enough hate will get regulated out, sooner or later.
I have played around with creating long form fictional content with Gemini 2.5 the last week, and I started adding "no one named 'Thorne'" to my prompts, otherwise it always creates a character named Mr. Thorne. I thought it was something in my prompts trigger this, but it seems to be a general problem.
However, despite the cliches and slop, Gemini 2.5 can actually write and edit long form fictional pretty well, you can get almost coherent 10-20 chapter books by first letting it create an outline and then iteratively write and edit the chapters..
I also used Gemini 2.5 to help me code a tool to interactively and iteratively create longform content: https://github.com/pulpgen-dev/pulpgen
If I was a better programmer I'd be working on that solution right now.