The quality argument against LLM-generated code has always seemed weak to me. Maintainers already review patches because humans routinely submit bad code. The review process is the filter.
Bad human code is usually fairly obvious, bad LLM code often less so, because it’s trained to produce superficially sensible-looking code. Hence reviewing it requires higher alertness and is more work. The other problem is that LLMs allow a human to submit much larger amounts of code to be reviewed than if they had to write the code themselves.