Drive-by wit doesn't get upvotes, even when it reflects HN groupthink.
More importantly, on contentious issues HN will still reward quality participation. Take ad blocking for example—you'll invariably see a lot of comments decrying advertising and associated upvotes. But you'll also see well-reasoned defenses of advertising that can also rise to the top.
HN has managed to allow different groups to interact somewhat civilly without resorting to tribalism.
Maybe the problem is what you consider "contentious"? I certainly wouldn't put ad-blocking in that boat. I would put "sexism in tech", "H1Bs" and "finance crimes" in that boat. How do they fair?
I'd say that's a nice collection of all the reasons my account would disappear somewhere else. As dang and tptacek described, there is an effect where they get hit with significant, sometimes massive, downvotes followed by more thoughtful people who valued a counterpoint that at least presented arguments or evidence. Plus a handful that agree with it probably. The sloooow upvote, but rapid downvotes, of some of those comments which would be popular elsewhere shows the site bias in action.
Critical to a parent's claim, though, is that those comments all survived with positive votes and sometimes continuing discussion. It's rare that I delete one for being totally ineffective. For me, high in dissent in contentious topics, I scrounged up 5000+ karma in a year without actually trying to get karma. That's clearly due to culture and moderation here that pushes for higher-quality discussions that are more tolerant of dissent than critics elsewhere say about HN.
For the latter two, you see a diversity of perspectives. There are plenty on HN toeing the populist line (H1Bs = evil, HFT = evil), but also people willing to go into the nuance and give oppositional evidence. Well-substantiated comments rise to the top even when they defy the populist thinking.
I'll concede that the former doesn't have good discussions, but I'm not sure it's possible to have a quality discussion about "sexism in tech" in any online forum. Saying the wrong thing will lead to you losing your job, but full anonymity brings out the trolls and the sexists.
Describe 3 good arguments in favor of the NSA you've seen on HN.
And as much as a lot of us here (myself included) think they're a net negative on the world, that doesn't mean they don't come with positives. They may not catch all threats but it's highly doubtful they catch none.
I'd wager that if you broke it down to the core elements, people aren't against the NSA but against the techniques they use: lack of transparency, gag orders, mass surveillance, etc.
And just to give you an actual third separate argument, the NSA existing keeps security in check. The threat of an entity that turns theoretical attacks into actual attacks means you can't get away with the "it'll never happen" excuse when building a secure system.
I'm asking you to recount specific instances when an NSA proponent did make arguments here, that they themselves held, at the risk of their own social capital.
As an example, I dislike prejudice and believe in a level playing field. This often puts me at odds with Political Correctness and feminism (eg. I disagree that sexism is a male behaviour (eg. The use of the term misogyny to reenforce this belief) and I condemn sexism by anyone). About 50% of the time I am modded down on HN. Challenging sexism from a feminist a guaranteed mod down at The Verge and a near certainty of being modded down at Ars Technica.
So, I consider HN to be more open minded than almost all other forums, save one. Many users on this other forum are mindful of the PC trap and discourage sexist terms like misogynist (instead of the more balanced, less political term - sexist)
I don't think anyone thinks that. The point isn't "HN is a utopia." It's "HN provides better discussion than most other places on the internet." On reddit, your comment probably would have been downvoted to hell by people who disagreed with you.
Does a "hacker type" correlate strongly with a certain race, gender or nationality? Is one political point of view more valid for "hacker types" than another? The guidelines of the actual site uses the qualifier "a good hacker," implying one should not only be a hacker, but "good" Good at what? Programming, startups, or conforming to an archetype of a "hacker" personality?
Even "intellectual stimulation" tends to lead to the belief that only intellects of a certain type should be considered valid. Dang has to constantly correct people who assume that content which is intellectually stimulating, but not explicitly about startups or technology, is off topic or detrimental. Hacker News is not what some people assume it is. The "good hacker" archetype itself is the problem, as people differ wildly as to their interpretations of it, and by extension, in their belief in what the true theme and purpose of Hacker News is.
Yet what really separates the average Hacker News user from the average Reddit user? I don't know how many users HN has, but Reddit has tens if not hundreds of millions, so one can assume the average Reddit user is not necessarily less intelligent than HN. Reddit also has a number of high quality subreddits which are heavily moderated and used by experts in their field, so I'm not certain HN possesses more technical acumen than Reddit, either. Quality of articles? Many things posted here also appear on Reddit.
Why, then, do Hacker News users seem to detest Reddit so much? Because among the few commonalities in the various interpretations of the hacker archetype are elitism and a distaste for mainstream culture, and new users want to appear to be "good hackers" and hating the mainstream is what people think "good hackers" do. Yet read the comments here, especially in controversial, non-technical threads where posturing as a "good hacker" has less value. Most are no better than, or even worse than, comments in similar subthreads on Reddit.
It's amazing that a former executive of reddit thinks a) it's easy to build a large online community b) it'll be easy to monetize (the hardest part) community and c) it'll be easy to moderate (hey people will do that for free, right?).