Do the conclusions change if we assume that the goal is not to optimize for value to the user, but for value to the company? Specifically, it seems that using the vote difference rather than the vote ratio would help controversial stories rank high. Controversial stories in turn are great at driving lots of discussion, which means lots of visits and revisits to the comment section.
(Compare to the apparent HN policy of discouraging controversy, both by the large effect of flagging and through the flamewar detector).
Possibly short term, but if you build a site around the kinds of people who like flame wars, your advertisers may notice they're getting very little traction from your site. Page views go up, but uniques go down.
Yishan posted a couple hours ago that Reddit's business model is built upon flamewars. Basically get people heated up and then they gild the comments they agree with.
...come to think of it, this explains a lot of the Reddit drama. The Reddit Gold was flying left and right during the black-out (despite pleas not to give any money to the site), and then every time an admin, CEO, former CEO, or board member pours gas on the fire, their revenue goes up. It's brilliant! They've figured out how to make money off of hurt feelings and angry people, and now have an incentive to cause as much drama as possible.
(Compare to the apparent HN policy of discouraging controversy, both by the large effect of flagging and through the flamewar detector).