I don't really like votes in general and never have, because they don't actually reflect whether something is correct. It often correlates, but it's usually just tilted to the subject/bias of the forum. (in one "leftist" sub saying russia bad will get you downvotes. in another one wanting gun control will get you downvotes. and in yet another one acting liberal at all will get you downvotes. usually there is someone willing to argue, though, in reddit fashion)

If people disagree vehemently they should state why so people understand. However, downvotes are also pretty good of getting rid of bad faith comments a lot of the time. But someone who is consistently contrarian (when they have a right to do so) will sometimes just end up getting auto-downvoted by all regulars.

I think there's also a bandwagon effect, even if it's subtle psychologically. That's not backed up by anything I have, though.