[spangry]

I think part of the problem is that many online discussion places (e.g. twitter, facebook, reddit, HN) implicitly reward people who 'react quickly' and who 'lead' (make 'root comments') over those that 'participate' (make a 'third-level comment', just for a random example).

On reacting quickly: in my experience, if you're among the first few to either make a 'root comment' to some post (on a medium like reddit or HN) you're much more likely to receive a large number of votes, positive or negative. And if you have even a slight preference for social validation, you'll play to the crowd by posting an agreeable meme or some variation. And the same goes for those who can quickly post the popular counter-meme as a second-level comment if all the first-level slots are taken. And bam, same old meme-based conversation plays out for the millionth time.

On participating: If you nest any further down than second-level comments, you tend to receive no reaction. No votes and often no replies, so it feels like you're talking to no-one (and you've just wasted a bunch of effort). And it's not that you care about chasing imaginary internet points; you care about receiving feedback that your comment has at least been read by a large audience. I suspect people who don't care about the latter are more likely to write in their diary. Consequently, the discussion can often lack depth.

So: rewards for 'quick reactors' + no incentive to add depth == shallow, pandering to the crowd comments.

I think it's something to do with the time-sensitive nature of these forms of discussion. Perhaps one solution would be to somehow mess with the interval between hitting the 'reply' button and when that reply actually appears.