[grzm]

Some people do use downvotes for disagreement. I don't think that's particularly productive. Members use downvotes more frequently for comments that are gratuitously negative, snarky, unsubstantive, uncivil, inflammatory, or violate the guidelines. I've seen a lot of well-balanced, reasoned comments on contentious topics that don't get downvoted (from what I can tell from the color of the text.

And yeah, there is are guidelines specifically related to downvotes.

https://news.ycombinator.com/newsguidelines.html

If you're wading into contentious discussions, be prepared for them. Take extra care to be considered and civil. If you do receive downvotes, consider them as feedback that you could do more to better express yourself. There's nothing you can really do about those who downvoted for disagreement. Commenting on that will definitely result in more downvotes, from what I've observed.