Too often, people talk past each other.
Too often, people nitpick like http://news.ycombinator.com/item?id=782752
Too often, edw519 gets upvotes for 'pithy' statements like http://news.ycombinator.com/item?id=864709
Too often, reposts galore, and even worse, from techcrunch: http://news.ycombinator.com/item?id=743735
Too much non-contributing irrelevant self-promotion: http://news.ycombinator.com/submitted?id=kkleiner http://news.ycombinator.com/threads?id=kkleiner
Too often, votes are based on... zealotry? http://news.ycombinator.com/item?id=902804 Why would jrockway get downvoted for answering a question as to why OSX didn't merit the Apple Tax for his purposes?
HN is useful for the domain knowledge and experience of some notable fellows, but a lot of the active user base dampens a lot of the remaining signal.