I've seen what you describe as "hissy fits" (and well-reasoned, substantive comments for that matter) come from all points of the political and ideological spec

I've seen what you describe as "hissy fits" (and well-reasoned, substantive comments for that matter) come from all points of the political and ideological spectrum. The most deeply embedded sociopolitical view I'm aware of is the natural human bias that "it's the $otherSide that's responsible for misbehavior".