As others have chimed in on at the risk of repeating, salting is a critical aspect of alpine, especially when the conditions are warmer than freezing. Safety issues can occur when high rate of speed and angles with too soft snow. Also, the conditions on a softer course can degrade rapidly, giving the advantage to those skiers that have an early start.
The salt, best i have been told, melts and then refreezes the snow into more compact, harder surface, eliminating a lot of the higher water content that will make the corn snow or slush. I also understand in many advanced race circuits, such as the world cup, they inject the snow with water to make it harder and last longer for the entire field of competition.