Ask Montee Ball how quickly most rookie RBs learn to pick up blitzes, and ask Peyton Manning how important it is. Moreno's our only everydown back, and I HATE telegraphing our plays to defenses by passing with the guy who blocks/catches but can't run and running with the guy who runs but can't block/catch.
Not to mention that the injuries to McGahee and Moreno the past couple years have reminded us how important it is to have a PAIR of everydown backs for when one is hurt or just tired. We've lost two huge games in as many seasons (i.e. last years playoff and @NE this year) simply because Moreno's flesh and blood and we had NOTHING behind him to ice the win.