One obvious counterpoint is that using AI tools allows manipulation of the discussion in a similar way to using a bullhorn in a coffee shop, only without revealing that you're the one holding the bullhorn. 10,000 bots "contributing to the discourse" in accordance with prompts and parameters controlled by one or a few individuals is quite different from the genuine opinions of 10,000 actual humans, especially if anyone is trying to use the discussion to get a sense of what humans actually think.

That's a good counterpoint and, IIRC, it's in addition to the other good counterpoints that I still can't find.