For example, non-native English speakers (as is the case with these guys IIRC) frequently use these tools. Maybe they shouldn't—as I've been telling a lot of people who email, mistakes are rapidly becoming a sign of authenticity at this point—but the belief that they need to is widespread, and this doesn't mean they didn't do significant work.

(Side note: it's a common assumption that machine-translated text is in a different category from LLM-edited text. From what we're seeing, that assumption is unfortunately completely wrong.)

Another important case is people with disabilities who find these technologies assistive. Again, one can argue that they're increasingly better off just posting their own writing in the raw, but this is a pretty obscure point to get across to people.

Beyond those cases, a lot of people just don't write easily, and/or don't feel their writing is any good. A lot of them are using LLMs to compensate for that, and this by no means implies that their work is bad. Maybe they just have a phobia about writing and/or don't express themselves well that way.

People who enjoy writing or are confident writers fail to understand how emotionally fraught writing is for many others.

Personally I'm down with the "writing is thinking" view, from which it follows that bad writing is bad thinking. But it doesn't follow that "thinking is writing" - that's a much stronger claim, from which it would follow that good thinking is good writing—and this I think is false.