I agree to this post, its quite obvious that if the author of the MR/PR has just submitted a vibe contribution (without even looking or testing) he/she doesn’t even care about the project, its a red flag.
I have contributed to a few open source projects and have been on the other side (contributor side) and I use AI to understand the problem, help me write a fix, but I do that in a worktree separate from the branch that I am working, I nit pick details that I think are important, it produces a lot of things, I examine each line and word carefully and have a lot of to and fro for understanding why it added it, usually the reasons are lame and on the lines of of course why not! I delete without thinking twice.
I think people are against using AI as is and not as an assistance for helping you contribute and solve the actual problem, if AI had solved it, why even the maintainer would require you to create a PR and all the overhead in between understanding your thoughts on this.