I think it's because people upvote most often when they share a particular opinion -- and your first opinion is mostly about the title of the article.

For example. I saw the title, clicked through (also opened comments), gave the page a once-over (didn't even read) -- came back here, and saw that first post. I also agree with the guy said, I thought they came up with some amazing new way to view regular diffs in 3D. So, I would have upvoted. Maybe it's just me, but I'm guessing far more people do that