You're totally on point, but I do think you're missing my wider point:
People replying with LLM responses is not really functionally different from lazily responding with a link. If the OP is astounded that LLM responses are tolerated, where was he all those years when people were lazily responding with links?
I am likely agreeing with you: but perhaps I just failed to follow what you were trying to say.
Perhaps it is a wider problem of "flipping the bozo bit", that someone perceives they are being treated as worthless (or worse) and then they respond similarly?
A considered AI response can be good if quoted correctly. Unfortunately I've seen a lot of AI-hate, where even fantastic AI answers (carefully vetted/curated) are shot down.