These trucks were engineered to carry a load. It doesn't surprise me that the drag link is only parallel to the ground when there is a load on the truck.
If they had designed for the drag link to be level unloaded, what would be the unintended consequences of the drag link being unparallel in the opposite direction when the truck was fully loaded? I am guessing bump steer.
I know one thing, I'd rather deal with a little bit of bump steer with an empty bed than any bump steer at all when fully loaded.
