May be un common for some people. but I personaly have suffered atleast ten cuncusions from skiing. one was so bad it numbed my left arm and the right side of my face. I could think of word to say, but could not speak them. I had a head ache for three day afterwards.
This is pre helmet.
If you don't ski hard enough, then I could see them being pointless. BUT TO CALL THEM STUPID IS WEAK!!!