I think this may be a consequence of HackerNews not having a downvote option for stories. I like the fact that they don't and I wouldn't suggest making the change but it tends to allow stories that have a higher dislike to like ratio to rise because the number of people who have an opinion are very high. This does tend to prevent some filtering of storied I do think should stay up on the top. It would be an interesting experiment to add a downvote to stories button to see what happened, even if that button didn't actually affect where the stories showed in the list at first.