One reason: if it takes 2 minutes to put together a PR, then you'll get an avalanche of contributions of which you have no time to review. Sure, I can put AI in fron to do the review, but then what's the point of my having an open source project?
> but then what's the point of my having an open source project?
For some people, the point was precisely to improve the software available to the global commons through a thriving and active open source effort. "Too many people are giving me too many high-quality PRs to review" is hardly something to complain about, even if you have to just pick them randomly to fit them in the time you have without AI (or other committers) to help review.
If your idea of open source is just to share the code you wanted to work on and ignore contributions, you can do that too. SQLite does that, after all.