Ironically, solipsist, the user who posted this, has an account less than a month old with 2120 karma. Based on my casual observation of the new stories page over the last month this user submits a lot of stuff. There's not necessarily anything wrong with that. But submitting a lot of stories is a good way to get lots of karma quickly, since stories are voted up more highly and it takes almost no time to do.

I agree that the downvote karma threshold has been instrumental in maintaining the quality of discussion here on HN, but it seems like it's too easy to get around by submitting lots of stories. And that drastically reduces the socialization period.