I find it frustrating that if I find a submission in the search result particularly nice, I need to visit the comment thread to upvote it. Why can't the search interface allow upvoting especially since it displays the arrow?
It seems you didn't notice that the search feature on HN (news.ycombinator.com) is actually handled on an external site (www.hnsearch.com). The tech behind the HN search feature (thriftdb) was created by the amazing folks at Octopart, which is one of the very early YC funded companies.