Although he did real work in physics, Hofstadter's fame comes from writing popular books about science which explain things others have done in more saleable words. That particular niche is seriously threatened by GPT-4. No wonder he's upset.
Large language models teach us that absorbing large amounts of text and then blithering about some subject that text covers isn't very profound. It's just the training data being crunched on by a large but simple mechanism. This has knocked the props out from under ad copy writing, punditry, and parts of literature and philosophy. That's very upsetting to some people.
Aristotle wrote that humans were intelligent because only they could do arithmetic. Dreyfus wrote that humans were intelligent because only they could play chess. Now, profundity bites the dust.