The design of HN is news oriented, not discussion or community oriented. And because it doesn't have categories, when the amount of submission reaches a certain size, up-voting "new" posts has marginal effect compares to random floods of submissions.
A year and half ago, I was reading every "new" post, because I wanted to be fair, but it's just not feasible right now.
If people were more selective with their upvotes the front page wouldn't be filled with <topic of the day> articles.
I have a hard time upvoting articles; Although I may have found an article interesting, I'm not sure if it deserves to be on the front page. I find it easier to say this shouldn't be on the front page (Lately I've found myself saying that about many of the articles that are).
Maybe flagging/downvoting articles should be promoted to keep things off of the front page instead. (don't think you can downvote articles)