It's a community note or reaction, rather than a reply. Replies are less aggressive because they are part of a larger discussion.

Forking is great for nagging and trolling. "This npub would like you to change your note to..."

And if they merge it, it's an overt and public act of submission, so that's very satisfying.

It doesn't even have to be mergeable. They don't even have to see it, for it to be fun. You could just write "You might want to switch out this photo for one that isn't ugly." on some girl's selfie and have a laugh with your followers. Like graffiti.

The process is the punishment.