Essentially any winter activity involves some resource output, short of cross-country skiing out of your back door. Sleds may be more efficient than many other vehicles, but generally 1 sled benefits 1 person. A skier may have to drive to their hill, but sledding generally requires that as well to reach a trailhead. And, to get there a large truck is probably necessary for towing and once there the activity requires an additional resource output for the single individual. While no ski area really does itself any favours by even operating, at least the number of people served is higher.
As for safety, here's numbers. Take a look at http://www.avalanche.org/accidnt1.htm
for stats for avalanche accidents and fatalities... you'll notice many more sled related events. For just sleds, it may only go to '02 but here: