The law (at least, in the EU) grants a legal right to privacy, and the motivation behind it is really none of anyone’s business.

Maybe commenters face threats to safety. Maybe commenters didn’t think AI companies profiting off of their non-commercial conversations would ever exist and wouldn’t have put data out there if that was disclosed ahead of time.

Corporations have an unlimited right to bully and threaten to take down embarrassing content and hide their mistakes, they have greatly enhanced leverage over copyright enforcement compared to individuals, but then if individuals do a much less egregious thing to try and take down their content they don’t even get paid for it’s immoral.