Are Macro Models Of The Economy Useful Or Even Good Theories?

This post is primarily for economists who are debating whether the macro economy requires a foundation in micro assumptions about human decision making. The post, and the comments that follow, illustrate some of the issues regarding the value of macro economic models based upon rational expectation assumptions. Frankly, I am skeptical of these models for another reason. Even though they have little practical value in predicting what might happen in the real economy, they are used to argue that government cannot affect business cycles because expectations will change when folks understand what government may do, and that will counter the actions taken by government.