I'm left handed and I believe that the wheel on the left favours left handers.
Picture this: A right hander holds the pistol grip of the gun while balancing the gun on on the left knee and turning the wheel with the left.
A left hander holds the forend of the gun with the right hand while turning the wheel with the left.
Granted the left hander has to come off the scope to see the wheel but I think that it's better ergonomically for left handers.