"The Chicken or the Egg" - Pass Rush vs Good coverage?

the Pass Rush is the most important for a few reasons.

1. It makes the QB speed up his progressions and try to fit the ball into tighter windows.
2. It gets the QB out of him comfort zone
3. The secondary doesn't have to cover for as long and can play tighter coverage
4. After some solid hits most QB's get rattled and don't play as well
5. The offense keeps more guys in to block resulting in less Recievers.

It doesn't matter if you have a dream team secondary (Deion Sanders and Aneas Williams, Charles Woodson and Revis at CB with Ed Reed and Rod Woodson at S) out there, if the QB has enough time eventually a WR will get open.