Respectfully, you are all missing the point.

Watermarking is bad not just because of the principled stance that your tool should not be working against your own interests (the passionate argument in TFA), but specifically because it lends credence to the idea that AI detection is a valid and possible thing to do perfectly.

As technologists of course we know "oh well yes but with some confidence interval we can detect AI token bias across a large corpus of text." To JimBob in charge of publishing your paper or reviewing your PhD submission, all he knows is "anthropic says AI detection is possible so this 30% chance your paper was written by AI means you've plagiarized." Do you really think you're winning the argument with the certified, law-approved plagiarism detection machine? No, you're not, and your career is over.

It's irresponsible to develop watermarking because it is not anywhere close to a perfect science, but it will be treated like one by people with the power to ruin your lives. Even if you've never touched AI in your life, your paper is going through the "maybe it says you cheated" box, and you better hope those dice don't come up snake eyes.