Not to stretch out this comment any more, but are we seriously arguing that adding a delete button is hard? I mean, most people on here would agree that its not something they would worry about. It sounds more like people are upset they are forced to do it, and have no say in it.
How want you add a delete button with out adding a complete login system? Or do you want to allow everybody to delete every comment? And of course this is also doable, but the question is, is it worth for a non profit (non tracking) blog? Probably not. Is it worth for Facebook and Google? Sure.
Exactly. I'm not arguing it's impossible, but that it imposes a meaningful additional burden on small operators without any real benefit to privacy.
Personally, I don't even think people should have the right to go back and delete a comment from years ago, which might have started a whole interesting discussion. But the EU requires that I think through such a system, including finding a way to identify them as the commenter and purge their PII from all logs/backups/caches as well.