Busnesses do not practice cencorship. They make business decisions.   You can agree with them or not agree with.   Consumers vote with their pocketbook.    This is the best thing that could have happened for Moore.    The film will be distributed by someone else, and he has gotten more publicity than he could have paid for.

After the film is distributed, consumers will again vote with their pocketbook on how many will see the film.   

Personally- I think if Michael Moore was one of the prisoners in the Iraq prison, most americans would have cheered.