Michael Moore is a very simple creature. He is a simple idiot with enough skills to put together a few films that appeal to folks who are unable to piece together their own point of view. The fact that many of his "films" have received awards as documentaries does not necessarily mean that they are true.
Documentaries have their basis in truth ... Michael Moore produces fiction. You may find his work entertaining and that's great. But anyone who believes that his work is an honest attempt to provide an accurate, truthful representation of history (a documentary) has allowed themselves to be snookered.