Are you sure you remember the McSorely play? The stick hit Brash on the side of the head near the ear in an unprotected area. Further, during the fall, his helmet was loose and Brash was unconscious before he ever hit the ice. I think you need to re-review that play as your memory is a bit off on it, TB. To say it was "stick to helmet" is just objectively wrong.
Further, the impact from that stick was far, far, far harder than the helmet. And, as many people have brought up, the stick has all of its weight up in the blade (along with the power behind whipping a longer object). A hockey stick is going to do far more pinpoint damage than a helmet will.