I think they should be banned, if there isnt a contribution besides what the llm answered. It's akin to 'I googled this', which is uninteresting.
IMHO its far worse than "I googled this". Googling at least requires a modicum of understanding. Pasting slop usually means that the person couldn't be bothered to filter out garbage, but wants to look smart anyway.
I think "I googled this" can be valid and helpful contribution. For example looking up some statistic or fact or an year. If that is also verified and sanity checked.
The contribution is the prompt.
I do find it useful in discussions of LLMs themselves. (Gemini did this; Claude did it too but it used to get tripped up like that).
I do wish people wouldn’t do it when it doesn’t add to the conversation but I would advocate for collective embarrassment over a ham-fisted regex.