for example, pg may not comment on obviously "hacker" stuff like php thread, but he might on 'non-hacker' posts like healthy food, stock market, etc
that's why i avoid (skimming) posts with php, python, ruby, windows, linux, gnu, oss, fsf, mac, osx, apple since the probability that i get great comments is approaching zero [over time]
Yes, there's a "comments" link up there, but i still have to manually search
My suggestion is that hn to have an alert icon where the list of my favorite "thought leaders" comment on the post - think about gmail's star
so if a post has a star next to it, then maybe pg and some thought leaders comment on it ... that post could be interesting
"always take the harder path" ... commenting is harder than upvoting