Is it due to HN policy? I guess they're subjective and ideological, and prone to starting arguments rather than debates.
Maybe "Please don't use Hacker News for political or ideological battle. That tramples curiosity." or "Please don't pick the most provocative thing in an article or post to complain about in the thread. Find something interesting to respond to instead."?
I'm honestly just curious as a conscientious internet citizen lol
Just to add one point, flagged comments are mostly flagged by users (as opposed to mods). We can only guess why users flag things, but from looking at a sample in the current thread it's probably because they're mostly flamewar-style comments and/or political-battle style comments (or both). Those aren't good for HN because what we want here is curious, thoughtful conversation.