I'm often curious why particular comments are down voted, so this caught my eye. Why did you come to the conclusion that it was due to a typo? That said, I don't have an alternative theory.
Maybe that's a more popular trend now? Having been active on HN for a long time and watched it evolve I guess I could see that...
Anyway, the branch of the conversation has gotten quite deep down the 'meta' rabbithole.