Whereas the base comment is fine - some things are delightful and there's nothing wrong with saying so.

As long as there aren't a bunch of "me too" comments, of course.

I agree that the former is clutter, but the latter is good, as long as the commenter is clearly trying to learn from/correct whatever mistake they had made. e.g. "This is being downvoted and I don't understand why. Could someone please explain the problem?" or "Why the downvotes? Is it because ...?"

I guess I prefer the fire-and-forget approach, only going back to edit my own comments for spelling and grammar ("EDIT: ... EDIT 2: ... is sort of grating to me). You make a good point though, and I don't believe that comment-self-awareness is universally an attempt at manipulation.