Except that it at least prevents the discussion devolving into a long chain of jokes, like you see on Reddit, and generally keeps this kind of thing to a minimum overall on HN.
There's a place for those chains of jokes, and that's mostly on Reddit (which I enjoy browsing often). But I would prefer to keep the discussion here on HN a bit more meaningful.
I think mkr-hn's point, though, is that Reddit may have joke chains, but HN has "tell-people-why-they-should-not-joke" chains. They're probably both equally time-wasting (this whole thread is a good example, and yes I'm aware of the irony of adding to it. Shit happens.)
There's a place for those chains of jokes, and that's mostly on Reddit (which I enjoy browsing often). But I would prefer to keep the discussion here on HN a bit more meaningful.