Why does our 5'6" receiver not do more comeback routes?

Just pure speculation on my part, but I get the sense that Payton has no clue what he's trying to do with this offense. Trying to run it 80% of the time, and we don't even really have a bruiser on the roster to do that kind of running. We've got two speed guys and a guy that can chunk it as far as they can run, but no one's open? Not sure what gives.