Well the idea is to NOT say “make it indistinguishable” (even if that’s inevitably the practical upshot) because the second you explicitly allow “indistinguishable” you open a can of worms arguing over what that means.

The same result unfortunately seems to be found by any attempt seeking this “middle ground,” because there’s always a cohort implicitly requesting that project maintainers bless their low-effort use of AI. (As to why this is, I’m not sure, but based on what I’ve seen would guess it’s because the AI use lets these individuals cosplay as developers.)

Regardless, that result is a huge influx of PRs which have obviously been submitted by individuals incapable of understanding, fixing, or taking responsibility for what they’ve submitted, which is an immediately intractable problem for project maintainers who already began with limited time to review PRs which, in spite of their varying quality, could at least be assumed to be understood by the contributor. Allowing any amount AI enables some amount of obvious (read: unfiltered/unreviewed) generated code, every bit of which is potentially problematic.