The latter are more wary of challenging authority based on their multiple experiences with it and have few illusions that civil disobedience and other forms of direct action will "radicalize" the masses - that is to say, their neighbours and workmates - in the absence of a social crisis. In current circumstances, unlike radical students and unemployed youth, they lose rather than gain credibility with their peers for confronting the cops - and possibly more than that if their actions become public and known to their employers. Mostly, their reserve is simply a reflection of their current state of political consciousness. The more politically aware workers presently treat demonstrations as an extension of their activity at the ballot box - another, albeit more vocal and visible way, of expressing disastifaction with a particular policy rather than a means of confronting a system which they still largely support.
Of course, if the population were being invaded and bombed as in Lebanon and Iraq or were abruptly stripped of jobs and savings as in Argentina or their marches to win the most fundamental democratic rights were being viciously suppressed by police dogs, fire hoses, clubs, and tear gas as in the US South, Palestine, and South Africa, their protests would assume a much different character than the polite "tea parties" derided on the list.
Large-scale protest is a function of the political context, something often overlooked by those aspiring to lead it who are more apt to blame its absence on the improper tactics and programs of their rivals or on the presumed inherent backwardness of the mass of the population.