Because their game plan almost beat a much stronger team (in my opinion) on the road. The Cowboys had the largest spread going into week 1, and the Giants came to within 1 point of beating us. They're game plan was spot on, and save some knuckle-headed decision-making in the last 2 minutes of the game, that strategy would have prevailed.
Now, I will grant you that a big contributing factor to the success of their strategy was that we kept shooting ourselves in the foot all night.
Still in all, the reason why I brought up the strategy in the first place was because it was designed to neutralize the pass rush (and did so pretty effectively).
If we look at the glass-half-full however, I am HEARTENED by the fact that the Giants felt compelled to abandon the big play all night in favor of the quick-release, dink-and-dunk stuff. They did this because they were afraid of our pass rush.
When was the last time a team had to design a game plan to avoid our pass rush?
The glass-half-empty side of this coin, however, is that our (potentially) strongest pass rusher is out for a to-be-announced timeframe (I'm waiting for the MRI before we begin sighing a collective breath of relief).
I hope they prove me wrong, but I don't see that fear of our pass rush influencing opposing game plans until after the bye week (which is all the more reason why we really need Demarcus to step up his game over the next few weeks).