I think a big part of it is the build up over last year's "success", and what was hidden in that being the reliance on the running game. Teams have adjusted to what the Redskins do, and what everyone seems to overlook, is just how EVERYTHING they did in the passing game was based off play action.
In the games that they have fallen behind, they have to rely on a less than healthy QB, who as a pure pocket passer leaves a lot to be desired. If he isn't able to make plays with his legs, and its obvious he is very aware of protecting himself at the moment, he just isn't the same threat. Make him beat you solely with his arm, and he is average.
Same thing is happening out in SF. For a different reason, but with similar results.