You can control your speed carving arc-2-arc turns, even on steep terrain; the choices within your control are very fast, faster and fastest. If you want to go fastest you release your COM from the turn early so that it follows a closer path to the fall line, if you want to go fast you keep your CoM going around the turn longer so that it deviates from the fall line (you can even make it go a little up hill before letting centrfugal force take it into the next turn. You can also vary how much you push your CoM down hill versus uphill and how much energy you use up "bruising" the snow.
Agree with "because on the places where the skidding happens, all you will find is ice", but that kinda avoids the point. Sideways skiing at speed imho is not only more dangerous and provides less directional control, but it is harder to do well.
Edited by Ghost - 12/3/15 at 1:12pm