Outside of Scott Adams and all of that. And I think public figures, especially those whose major schtick was to engender reaction, are a different story.

But it's basically getting the last word in because the other party is unable to respond. It's seen as a little uncouth.

On reddit, it's kind of like those people who respond, then block you to make sure you can't respond. They aren't there to make an argument or convince you, they just want to get the last word and they're doing it in a way where you cannot respond.

Like I said, I don't entirely agree with "don't speak ill of the dead". Especially for figures who used their platform to elicit responses. But that's one of the reasons behind the sentiment. Right, wrong, that's for you to decide.