In the short term, making sure junk threads like this fall off the front page of the site (or to the bottoms of their threads) quickly is an important goal. That protects the site itself, by preventing it from collapsing in on itself due to pointless hostility. This is the problem the HN mods have been working on for the past year or so.
In the long term, figuring out how we can host relevant discussions about volatile partisan subjects is important, and I imagine something that will become a focus for moderation.
Not having completely solved the first problem, it's probably a bit wishful to hope that we can address the second one.
HN doesn't have to be all things to all topics. If we lose some stories in the service of repairing comity, I think that's a fine tradeoff in the short term.
If you can get past the title, this is actually a very excellent article on moderation requirements for a successful online community: http://dashes.com/anil/2011/07/if-your-websites-full-of-assh...
But there are worse things than being an echo chamber, and preventing those worse outcomes takes priority.
The irony about the link you provided is that HN does literally all the things Dash says sites should do. Of course, the problem HN faces is much bigger than the problem Dash is contemplating.
But there are worse things than being an echo chamber, and preventing those worse outcomes takes priority.
I would disagree on this, but I see where you're coming from. HN serves a lot of purposes to a lot of people.