The more recent data has no such connection. It seems that the influx of users reduced the quality of judgement.
So one way to improve HN submissions and comments is to weight points by the user's tenure on HN.
I also suspect that early comments dominate late comments by the time factor alone. The sorting algo gives a brief advantage to new comments, but old comments are more visible. A post on the front page gets 30+ comments in the first hour, and latecomers can only post into the void. To address that, long branches could be collapsed by default, leaving only 2-4 visible messages per branch.