I assume it gets flagged because because it's off-topic and not a new phenomenon. You see the same arguments/comments/flames on every post that comes through here. At least if it was about some new proposed system, fundamentally new analaysis/data/tech, then it would be on-topic.

Because it's off-topic for HN. From the HN guidelines linked at the bottom of the page:

"Off-Topic: Most stories about politics, or crime, ... If they'd cover it on TV news, it's probably off-topic"

It is an insanely divided topic that leads to heated exchanges which is not the kind of dialogue HN is trying to cultivate.

I didn't flag it, but this is definitely the kind of topic that nothing good will ever come out of on HN. (Alas?)