I will try to illustrate the difference in the ski hills and the "skiers" these hills create using two examples from my experience.
The eastern hill is Callabogie peaks,http://www.calabogie.com/content/winter_mountain.asp
though it now has snow-making equipment, it didn't when I learned to ski there. The runs are steep enough, though not very long. the vertical, touted as the greatest in is 760 feet. The runs are often quite icy. They are very well defined, there is next to no skiing done that isn't on a groomed trail or on ice.
People who learn to ski on the eastern hill get very good at skidded turns very quickly, as there is nothing to prevent the skis from skidding. Pivot turns can easily be practiced on the crests of small bumps. Catching an edge doesn't happen too often. The snow, when it is not ice, is man-made artificial snow which is pretty solid underfoot. Carving can be learned, and the skis can easily be set on edge. The bumps are usually quite small, no more than waist high, and even if you can't ski around them you can ski over them hitting every 4th one. You can not get up to a great speed, because of the need to avoid other skiers, and the lack of any straight, long steep. However stability is a problem due to the hard icy conditions; there is little natural snow to damp out vibrations. By the end of the day, many of the runs have similar conditions to race tracks.
The western hill is Mount Washington on Vancouve Island,http://www.mtwashington.bc.ca/winter05/alpine/
The vertical is not as great as at other western mountains, but it's still more than double Calabogie's. The snow is natural and usually very deep. You can be skiing with your skis a foot under the surface. You cannot make a skidded turn very easily in these conditions, though applying the same motions will get you turned if you are going fast enough (much like water skiing). People who learn to ski in deeper softer snow learn to carve pretty quickly, they generally don't learn the skidding side of things quite so quickly. The soft snow gives way underfoot, so if you angle your skis, the snow will crush under one side and you can "fall off" the snow underfoot and find yourself suddenly sinking deeper and tripping. Any edges misplaced will make you fall, so you learn good form quickly, you cannot "muscle" 200 cm of ski when it is loaded up with snow, like you can if it's sitting on top of ice. Westerners generally have good technique, because they can't get away with poor technique. Though they have a trail map ( http://www.mtwashington.bc.ca/winter.../trailmaps.cfm
), and they have runs, at the top of the mountain, it is all snow and hard to tell exactly what trail you're on. For example if you go to the left at the top, you won't know if your in western basin or westerly or even Powderface until you ski down a bit. There is (at least not when I was there) a well defined trail, you just choose how steep a start you wanted and found out where you were later. There were also bumps about 12 feet high the last time I was on Powder Face.
So in a nut shell Eastern= icy, skidding expert, Western off-piste, and deepsnow expert, but that's just the start, there is no reason skiers form east and west cannot progress to all levels and techniques.