Earlier quoted context omitted.
Really surprising to see that comment, which, full disclosure, I agree with, get flag-killed. I wouldn’t be surprised to see it get a few downvotes. But rarely have I ever seen a thorough, well-sourced, and civil comment actually be flag-killed. If anything, the shallow replies to his comment are the type of things that typically seem to get downvoted (though not necessarily flagged either).
I think this is a side effect of self-moderation. By making everyone in the community (over a certain threshold of participation) a mini-mod you turn rules enforcement into a popularity contest. Valid, interesting, yet unpopular points get suppressed. Rules violations that are popular get ignored, and sometimes even lauded. There is no reason, based on the HN guidelines, that the referenced post should have been down…
This "drive by down-voting" happens regularly here. I've had comments downvoted within seconds of posting--clearly the voters could not have had time to read the entire text. They see a few key words that trigger them, hit the arrow, and move on to the next job. Unfortunately, there's no way in JavaScript to tell whether someone's actually read the thing they're down-voting, so we get these knee-jerk keyword-based brigades.
To test this, sometimes I'll write something where the first sentence is provocative, but the rest is (I hope) a solid, nuanced argument. Usually it's at -1 or -2 within a minute, and then over the next few hours slowly crawls back up to +2 or +3 as people actually read it.