Because you don't want to deal with people who can't write their own code. If they can, the rule will do nothing to stop them from contributing. It'll only matter if they simply couldn't make their contribution without LLMs.

Because they aren’t accountable - after it is merged only I am. And why would I want to go back and forth with an LLM through PR comments when I could just talk to the agent myself in real time? Anytime I want to work through a pile of slop I can ask for one, but I don’t work that way. I work with the agent to create plans first and refine them, and the author of a PR who couldn’t do that adds nothing.

If your doctor told you he used an ouija board to find your diagnosis, would you care about the origin of the diagnosis or just trust that he'll be accountable for it?