Speaking for myself, I've never gotten any real value from an LLM and their disappearance would not affect me in the slightest.

It sounds more like you were upset about his assertion because YOU derive value from an LLM, and are projecting that as some sort of dishonesty on the author's part.

Also, it was his intention to throw "the kitchen sink at the technology" as a means of showing its lack of value. In the same way a vegan would do exactly as you mention to show all the arguments AGAINST eating meat. It is meant to strengthen the intended argument through overwhelming evidence.