You're absolutely right! (/s)
The tone of AI-written stuff sounds to me just like the soul-less SEO-optimized content marketing blog crap we saw the years before AI became a thing. Very prevalent on Linkedin too. It just sounds/reads so hopelessly artificial.
If I were to begin using AI to write stuff for me (comments or articles or whatever), I'd at least begin with having it train on the collection of everything I've written so far.
This makes sense and is extremely possible and how I thought these things would be positioned in the first place. In surprised we don't see this more - would be better results, less shame thrown at users, and make the product stickier.
SEO slop is what the LLMs were trained on. GIGO