I agree with what you said, but my presumption has been that the HN status quo would generally be receptive to the argument that u/paulmd made, or at least, not offended/angered enough to flag it. Especially it being so well-written, and in response to someone whose argument was entirely speculative or based on emotional appeal, and who didn't bother using basic capitalization or punctuation.

It's even more surprising since HN had the "vouch" feature since before Dec. 2016 [0]. My best guess is that people might have reflexively downvoted/flagged upon seeing the opening sentence of "Black people are measurably less likely to own a car or have a bank account".

[0] https://news.ycombinator.com/item?id=11589410