I'm not sure, but I try my best to assume good faith / be optimistic.
This one hit a sore spot b/c many people are putting time and effort into writing things themselves and to claim "no ai use" if it is untrue is not fair.
If the author had a good explanation... Idk not a native English writer and used an LLM to translate and that included the "no LLMs used" call-out and that was translated improperly etc
To me it's another specimen in the "demonstrating personhood" problem that predates LLMs. e.g. Someone replies to you on HN or twitter or wherever, are they a real person worth engaging with? Sometimes it'll literally be a person but their behavior is indistinguishable from a bot, that's their problem. Convincing signs of life include account age, past writing samples, and topic diversity.
Not disagreeing with you, but out of interest, how could you be convinced otherwise?