I think nobody is upset about reading an LLM's output when they are directly interacting with a tool that produces such output, such as ChatGPT or Copilot.
The problem is when they are reading/watching stuff in the wild and it suddenly becomes clear it was generated by AI rather than by another human being. Again, not in a context of "this pull request contains code generated by an LLM" (expected) but "this article or book was partly or completely generated by an LLM" (unexpected and likely unwanted).