I am convinced that the combination of voting up good comments with strict, clear and fair moderation is an important reason. Add to this that reputation among peers may matter to people and maybe that is the formula.
I have also seen people say some pretty absurd things using public Facebook comments that have their real name and details attached to them, I don't think people are considering that they may be making some career limiting moves when they get mad in comment sections. I also think that tech people have a lot more job options and freedom of movement between companies than other careers.
Sites like reddit that gather karma also create a "reputation" scenario for users, yet it still contains trolls, so I don't think it's that either, but it may be a contributing factor. That combined with the broken windows theory and the very specific target audience may be what make the comments mostly civil but certainly not immune to parody.
So that helps.
Politics and economics and ethics are inextricably intertwined with technology these days, so it's usually on topic to comment about the political aspects of a situation.
i dont think that's really the case. HN is full of middle/upper middle class programmers who works in well-developed countries. This is definitely a segment on the political spectrum. This is why you don't see many trump voters here, or bigots or the very conservative. Anyone who attempts to bring discourse with such an undertone will get downvoted.
I'd say HN has more groupthink than the people here would care to admit.
No, it's not. While class and profession have some loose correlation to ideology, the class/profession combination you describe includes people from all over the political spectrum, including all of the ones you say are excluded from HN for this reason (whuch, contrary to your description, seem to be well represented; well, not overt bigots but HN moderation is aimed pretty directly against that, and perhaps merely Trump apologists, who may or may not be Trump voters.)
I’ve whitnessed threads where users were basically going “no politics pls.”
Maybe the threads that I end up clicking on attract certain kinds and the threads that you’re on attract other kinds.
Not getting too heavily invested in any one comment helps, as does addressing any responses strongest rather than weakest points.
I'll call out (and occaisionally report) comments thaat eem unjustly downvoted. Sometimes (frequently) the mods agree, occasionally they don't.
There are also numerous shadowbanned accounts. It is possible to vouch their positive contribuions.
HN isn't perfect, but it's better than a tremendous amount of the Web, for discussion.
I've discussed this before in a direct comparison to a "kinder, nicer" site which proved to be neither.
Moderation and site dynamics are curiously subtle.
https://www.reddit.com/r/dredmorbius/comments/500ysb/the_imz...
(1) The culture started by Paul Graham, back when he used to write lots of essays, emphasized a certain "hyperrationality" and attracted a lot of super-logical people in the beginning.
(2) Heavy moderation to keep things from deteriorating and discourage overly polemical debates.
The bottom line is that people quickly get an idea of what is tolerated and what is not tolerated so they work to stay in line which doesn't seem to happen as much on other websites.