The problem with tone policing is that it encourages groupthink, because deviating from consensus assumptions is intrinsically aggressive (no matter how well-couched) while extremely-low-effort agreeable comments pass right through the radar.

I understand if the point is simply to keep threads from devolving into sequences of "no yuo", but I did substantiate my call-out with the larger meta-intellectual point being brushed aside. What makes this story "interesting" is the editorialization of services that have traditionally been viewed as conduits, not because it's a place to pile on anti-discrimination piety.

That argument doesn't hold up empirically. Plenty of HN users are able to disagree substantively without resorting to ranty rhetoric like you did in your last paragraph, and the disagreements are better for it.

Lofty descriptions of nobly pursuing truth ("deviating from consensus assumptions") against the groupthinking mob (everybody else!) are mostly self-flattery. People don't post ranty rhetoric because we want to strengthen diversity of opinion or anything like that. We do it because it feels good to vent. The problem is that others take it as a license to vent further, and by the time that process converges, it's all in flames. Flamewar is the ultimate groupthink, by the way; despite what the war parties say, it's always the same.