This is all I could find on short notice.
Marcel Hirscher Net Worth
Bode Miller Net Worth
Lindsey Vonn Net Worth
Shaun White Net worth !!!
Looking at these stark contrasts (Shaun White annual earning being almost equal to the other 3's net worth, and his Net Worth dwarfing their combined earnings), I guess if you are an advertiser looking to associate your product with the snow sports industry, you're considering a far broader range of options than once existed, and WC alpine racing has steadily diminished (at Home and abroad) as other branches have grown. Companies aren't inclined to over saturate a field, so, there is only so much 'snow-sport culture market segment' advertising money to go around.
Also, as in other sports (mountain biking being the most specific), consumers (and that's what matters) no longer revere racing driven production they once did, for a multitude of reasons, both good and bad.
Finally, FIS-WC racing suffers from the same problem many of these entirely sponsor driven sports (with no large 'paid viewing' fans-as in a large paid-seating arena/ stadium driven sport): The earnings are outrageously Top-Heavy. This is true in Motorcross (the biggest money version of these sports) through all manner of competitive skiing. Top 5-10 so vastly out-earn everyone else (as the sponsor money is ALL of the money), that it is hard to generate enough star power across the whole spectrum of competitors. You're better off getting Mikaela to wear your logo than putting your logo on the whole event.
And one wonders, how much dollar in dollar out return is there in investing in WC racing sponsorship. Back to Hirscher, he's been the best technical skier on the Planet for a few seasons now…How's atomic doing, and does he actually sell more skis for them than Bentchetler (whose name alone actually sells skis, literally)?
Just some thoughts. I think the whole 2008 global economic Shake-down has pushed corporations to think more deeply (and undoubtedly more big statistically) about where best to put promotional funds to generate the best returns (a lot of sports have seen a real diminishing of corporate money). If there is a decline in WC sponsorship (and don't know that there is), it's roots lay in the new reality.
Markjop: Last Season Tina Maze and Marcel Hirscher were the Top earners (in competitive winnings, with MAZE setting and all time record) each earning roughly $500,000. There's just not that much money in the sport to begin with. For Comparison, Here's a list of Top winnings leaders in Golf for 2014 (a season that's not entirely over I might add) Golf Leaders