I promise you that you have merged PRs with AI generated code and/or comments. You just couldn't tell because the contributor wasn't a lazy idiot and actually thought about how to use the tools at their disposal to do good work like a professional.
I swear if we left things to you people, we'd all still be programming in assembler. Copilot generates most of my commit message drafts now. I end up accepting about half of them without needing any modifications. Sometimes they're shit. That's why I'm the developer and author. I always make sure whatever PR I submit in my name is something I'm proud to stand behind. But sorry that you don't want me on your project for that sin of the tools I chose to use for my work.