I disagree. People will frequently say that downvoting is not for disagreeing, but in every controversial thread dissenting opinions are quickly downvoted and frequently flagged. Some recover, but many die or end up pushed down into obscurity.
Mildly controversial opinions sometimes survive and get discussion, but anything past that rarely get a reply and just get downvoted and flagged into oblivion. This isn't exactly a slight against HN, as this happens basically everywhere past a tiny userbase community. But I don't think it's particularly right to put HN on a pedestal for its ability to handle controversy.
There are over 1,200 comments on this controversial story alone, with plenty of debate within: https://news.ycombinator.com/item?id=43517833
What more evidence do you need that spirited disagreement is alive and well here?
Downvoting for disagreement has always been fine on HN. People sometimes assume otherwise because they're implicitly porting the rules from a larger site, but that's a mistake.
> People will frequently say that downvoting is not for disagreeing
Those people are wrong.
>> Disagreement is alive and well on HN.
> I disagree.
Head explodes
I would also argue that shutting certain posts down early is what helps it thrive. Maybe you lose some value of topic but you gain the ability to discuss other things in depth. You also prevent pollution of discourse.