Why would Chinese censors have a problem with films making fun of American capitalism and imperialism?
Anti-rival sniping is comparatively boring and we're all steeped in it all the time, anyways. It's the furthest thing from counterculture.
Avatar was viewed by some as being about problems in China relating to demolishing people's existing homes to build new buildings in their place. There was some discussion at the time that they only allowed it due to being the top grossing movie of all time.