Earlier quoted context omitted.
I'm not sure why: edw519 could easily and reasonably think that what Aaron did was wrong while being very sad that he committed suicide.
A more cynical observation is that users with high "karma" point totals earn this by parroting the majority opinion or otherwise treating comment threads as a game.
So, to an outside observer, you might suggest that these users game Hacker News but the real answer is that they have an audience. It's debatable whether that's their fault, on a case-by-case basis, though.
Then you could probably say it goes the other way: a large part of the community feels a certain way because Ed says so (in the top position), or Thomas says so. I've noticed the atmosphere of a thread change after a comment from a "well-known" person is left, rather rapidly on occasion. The momentum of a community like Hacker News is an interesting study, and although I didn't get an opportunity to watch the thread under the microscope, I bet a large part of it was shaped by Ed's comment.
Recently I've learned how Hacker News threads are living organisms, and I've noticed the impact of the commentary that I make. If you pay close attention, you'll be surprised at how the thread evolves and grows, particularly based upon what's in the top position.