That's part of what I love about the NFL. For all the pass-happy schemes and attention that QBs get, at the end of the day if you cannot run the ball and defend the run in the NFL, you are toast.
Running up the middle and gaining good yardage is one of the harder things to do, but if you can do it then that threat is something the opposing defense HAS to account for on every play. Likewise, it's also one of the easier plays to defend, and if your defense can't at least put up a fight in the middle of the trenches then that will filter down to the rest of your defense.