alt Hacker NewsAI detectors are only harmful if you use them to convict people, it isn't harmful to gather statistics like this. They didn't find many AI written paper, just AI written peer reviews, which is what you would expect since not many would generate their whole paper submissions while peer reviews are thankless work.
If you have a bullshit measure that determines some phenomena (e.g. crime) to happen in some area, you will become biased to expect it in that area. It wrongly creates a spotlight effect by which other questionable measures are used to do the actual conviction (“Look! We found an em dash!”)