But this has always been my point regarding running the ball. A team must run effectively or they won't be able to pass well. When a team realizes you are no threat to run the ball, they pin the ears back on first and second down. This makes the OL job impossible. Plus, running wears down a DL, passing wears down the OL.
If you have hopes of picking up 15-20 yard chunks to flip the field you have to run well. And if you are REALLY good at running you can eat up field position and wear down a D at the same time.
The flip is also true. You must be able to throw the ball at least well enough of a D will stack 8 in the box. If you can't audible to a pass and punish them you're done.