Naive question - isn't direct linking to encourage votes kind of making the HN magic sauce of scoring upset and driving the entry to never get on the front page?
I imagine the goal isn't to encourage votes (since as you pointed out, that wouldn't work), but rather to point to any HN discussion of the article.
Edit: I was looking at the wrong thing, yea it's weird that it says "Vote" when votes wouldn't register if they came from the site.