Here are my two points: Tricks can't be played. Why? because ya might as well be able to do it all. How can pretzels be played? There are so many variations, if you can't pretzel, you probably can't ski rails... Are people just supposed to spin the same direction or do a tail press every time? Nawww. And if you want to win contests, lets face it, you have to be able to spin fast and double flip. You might as well learn how to kangaroo flip if you know it will impress the judges and thats what you want to do. No matter how shitty the roo flip can look at times, you almost have to be able to do it or close to it for major contests. If the trick is fun, or you want to impress the hot chicks on the lift you might as well do it.
Second point: Just because you want to get sponsored or make a promo doesn't mean your skiing for money or whatever. If you really really love skiing, then you probably want to be good at what you love. The way to prove to yourself that your good at what you love is winning contests or having a companies support aye? A last couple thoughts, a sponsor can help you get to contests or save money to do what you really love so I think the people putting all the effort into promo vidoes are probably the people that love skiing the most.
Well anyway, you might not agree and I may be wasting internet space but I felt like sharing!