In the original reddiquette, it mentions downvotes are not meant to be used as dislikes, but for content that is not relevant to the subreddit (or community in our case) or discussion – if it doesn't add anything of value. That gives the community the ability to push down and essentially hide things that aren't meant to be there. A sort of community-powered moderation for things that aren't entirely rule-breaking.

For example, someone posts a cute cat picture on a programming community. Is it cute? Do I wanna see more? Possibly. Is it relevant to the particular community? No. It could also be useful to hide particularly bad or wrong advice given as a comment.

Unfortunately, as we all know, it doesn't work that way. Downvotes are used like dislikes. And probably have also been used at reddit heavily by bots to influence what the public gets to see, and what they don't. I think the mechanism is useful, but it may need to be re-imagined.