It's not really pedantic when there's an entire wikipedia page on the tendency for people to conflate the two: https://en.wikipedia.org/wiki/ELIZA_effect

I believe the distinction they're trying to make is between "sounding like a human"(being able to create output that we understand as language) and "thinking like a human"(having the capacity for experience, empathy, semantic comprehension, etc.)

But nowhere in the original post was there a mention of "thinking like a human". The poster said that these systems, at their core, emulate human behaviors. Writing is a human behavior - as are all the things that are requirements for writing (operating within the rules of given language/s, making logical choices, etc). The things you listed as evidence of human thinking were never implied when talking about replicating what human writing is.

I can only assume that either they are trying to point out that words aren't behavior, and mimicking human writing isn't the same thing as mimicking human behavior, or it's some pot-shot at the capabilities of LLMs.