I don't think the problem is the subjectiveness as much as the knee-jerk reaction. If you're in a heated argument with someone, most any human's first reaction

I don't think the problem is the subjectiveness as much as the knee-jerk reaction. If you're in a heated argument with someone, most any human's first reaction given the ability to "punish" their opposer will be to click the downvote button. The mental heuristic, in our case "anything that good hackers would find interesting", just never gets run. It's effectively dead code, because the stack of "do I agree with this" if/then blocks happens a few hundred lines up. It takes a lot of effort to override that reflex.