Indeed. Downvoting simply shouldn't exist. It lets users feel like "mini-censors" and it turns out people really like censoring views they don't agree with or that make them uncomfortable.

It's not just downvoting, though. Reddit also lets the moderators act like real censors and they are completely unaccountable. There is no way to visit a subreddit and know whether the discussion there is censored or not. So you have to assume it is.