Actually, a lot of the movements have addressed the political source of the problems. Some of them locally (A lot of Occupy Oakland's rhetoric has been against the decisions of the city trade council and its mayor) some of them more universally (occupyDC has drafted a deficit/jobs bill in rough, and is currently petitioning and protesting to get it through, http://october2011.org/99 )

And the squawking itself also serves a purpose. Because a blind monkey sees a lot better than the legislative bodies of most modern nations, if the rhetoric and bills and such are any indication. Sometimes you do have to create a lot of noise to draw attention to a problem.