Okay, so a quarter back is a defenseless player, I get that.
So where can you hit a quarter back and how hard? If a QB see's a defender and lowers his own head to protect himself, and the defender hits him with a part of his facemask or his helmet "who's fault is it"? Why are QB's still being protected outside of the pocket when RB's are hit helmet to helmet on almost every play?
My understanding; A QB cannot be hit to high or to low on any given play.
I see this as a way of slowing down these monster defenses and keeping the offense on the field.