But he’s made the error of trying to come at it from a technical perspective, when he clearly knows nothing about that side of things, which discredits the rest.
Huh? That quote appears to be the entirety of the "technical perspective" of the post and is an aside from his larger points that you have blessed as "fine". Literally nothing in the rest of the post relies on that incorrect statement.
Let me quibble with what is discredited here, given the entirety of your point is built upon an error.
> They're word-association mechanisms with no embodiment and no way to associate the text vectors they manipulate with real-world phenomena.
This is wrong too. RLVR grounds foundational models in reality.
> no way to associate the text vectors they manipulate with real-world phenomena.
Historically, that LLMs were text-only used to be a major argument for why they "lack access to meaning", see the Stochastic Parrot paper and the Octopus paper that it references. But even the authors of those papers have (grudgingly) conceded that the argument no longer holds due to multimodality.