> AI writes unmaintainable code - you can see that many projects don't accept it.

There also exist other good reasons why projects don't want AI-generated code, in particular

- because of unclarity of copyright status and consequences of AI-generated code

- because the project leader simply made the observation than many programmers who hand in AI-generated code care more about "getting things done" and "pushing through their changes" (possibly to boost their CV) instead of deeply caring about code quality

To be fair, so do humans.