On another similar site with much more lenient free-speech, with tens of thousands of upvoats I've made to others' comments, I've only done a couple hundred downvoats. So about 1% down. Of my voats for submissions, a little more than half a percent weren't upvoats. So not a very essential feature.

Technically it's the same. The point of the system is to allow a group effort at grading content so people with less time can focus on the best stuff. You don't need downvotes for this.