Comparing this to off-piste skiing or mountain biking is not fair at all. You can view avalanche predictions, sample the snow pack, and take safe and slow lines that go perpendicular to the faults when skiing. Biking you can use hydraulic disk brakes, deliberately lay the bike down and slide out, plus you should be wearing a full face helmet, spine + neck protector, and other armor. Unless you are actively trying to set a speed record or win a race there is far less danger.