Liberalism as mental disorder

I am only partly kidding with my cruel title. And yet, it is astonishing how true the aphorism rings that I just read moments ago, plastered on a lamppost around the corner from here:

In a political economy of ruthless competition, the rightwing destroy the world, while leftists destroy each other.
-RiotCop

For example, otherwise comfortable, middleclass people can be simultaneously terrified of the consequences of pollution and environmental destruction, for themselves, their children, and their elders, and moderately responsive to leftwing analyses of the problem, but simultaneously even more afraid of the dangers of losing some measure of bourgeois "respectability" by appearing to get too exorcised over the matter, or heaven forbid speaking hastily and getting anything factually wrong in their passion about it.

In reality, though, it has always been precisely when people got sufficiently pissed off and "unreasonable" as to make life a little bit unpleasant for the power brokers, that concrete concessions have been won. Appearing "reasonable", "moderate", and modest in their demands has never accomplished much of anything, other than getting steamrolled.

What is it about the people in the socioeconomic "middle" that always seems to make them the scaredest pussycats around?

Folks at the bottom rarely raise their voices on anything, being too busy mostly with just surviving to have the time. When they do, its usually in the news, think riots in LA or Milwaukee, scaring the bejesus out of the comfortable everywhere. Folks at the top feel free to pursue the most extremist antisocial agenda in favor of their personal self-interest with hardly an eyebrow raised and few consequences. But folks in the middle? You are exceedingly lucky if you can get them to sign a petition between breaks sipping their latté.