Well, most of the time movies have little to do with politics, which doesn't explain why his momumental To Live was banned in China, now does it?
Most movies are just for entertainment, but perhaps you've forgotten that the opening salvo of the Cultural Revolution was a critique of a play that appeared in a newspaper.
http://www.guardian.co.uk/china/story/0,7369,1682269,00.html In many ways China has modernized beyond recognition in less than a generation, but to think that the dynastic power plays have gone for good is to underestimate the power of thousands of years of history.
As for a movie that's entertaining, what's entertaining about seeing a rebellion against a dictator brutally crushed? There is of course valor and bravery even in defeat- but why did the Empress ensure defeat by letting the crown prince warn the Emperor? Indeed, the only character of any humanity in the film is humiliated- the only way one can have any sympathy for the Emperor (whom Chow Yun fat does incredibly well), is if one believes that stability, if that includes poisoning his wife for no known reason, must always prevail. And what happens to this emperor in the end? None of this is explained well.
Otherwise, it's a spectacle. Another poster's comparison to Cirque du Soleil is perhaps apt. But one expects more from Zhang Yimou.