Why did the major media wait until the Friday the movie previews to do a review ? Isn't the answer obvious to you ?
Free advertising to get the curious sheeple into the theatre to find out what all of the hoopla is about !
This kind of high level exposure on the opening night of his big lie is priceless to Moore and you can bet he is in his penthouse apartment thanking his lucky stars to have such loyal friends.
Of course the media had to diss what was an obvious and stinking effort to unseat Bush. They had no choice but the payoff will be THE BUZZ. They learned well from their lesson dealt earlier this year by Mel Gibson. They key to generating interest is to generate as much negative controversy as possible to get the rubberneckers' attention.
BUMP
I think your example of the Passion proves you to be seeing what you want to see. Most movies don't get reported in the media until opening night, and then only if they are notable. The Passion was highly unusual in getting weeks, even months of media controversy and hype before the release. If the media were pushing and hyping this film more than it deserves, they'd have covered it more and sooner with more controversy to get the Passion effect you speak of.