i'd suggest wearing one, and like you said, anyone trying to promo otherwise is kinda dumb.
this is a mate of mine. stopped on the piste to wait for others. set off again, hadn't gone 50m on a blue run and caught an edge (snowboarders ehy?). There was the standard padded poles with netting stopping people launch into a cliff on the left side, but due to his rotation, and a minorly slack netting he caught his head on the 90 degrees of the metal pipe with no padding.
had a seizure on the mountain for what i thought was far too long, then suddenly stopped. that was the scariest part and he was super white in the face. kept him there whilst we got the blood wagon guys.
i'd wear a helmet