I beg to differ some. Developers have a vested in certain types of housing in ski towns...high end properties that will net them more $. Sustainable development that includes a range of property types would help accommodate not just the uber rich...but those in the middle and the service providers at the bottom. They don't create the demand, but the way they help fill it has a huge impact on housing and real estate in the these locations.
Sustainable development doesn't exist outside the laws of supply and demand, though. If there's enough demand, and not enough homes being built, then all housing will be luxury housing —including everything in that range of property types you describe. For example, someone in this thread I think posted about a $700,000 shack in Bend, Oregon. If a developer built a new shack in Bend, Oregon—no over-the-top luxury features— do you think it would be affordable? No, probably not. Empirically, more supply of homes reduces prices (See studies by Pennington, Lee, Asquith/Mast/Reed).
What might complicate this is that ski areas are, by definition, tourist areas. They can be different than other places, so the housing market may or may not have different factors here. So I'm not totally ruling out the possibility that developers may, in fact, be inducing demand in some of these areas. I'm skeptical though because it would be an exception to the general rule. I'd want to see a study about it
That said, it seems that an immediate housing subsidy for resort employees is the right thing to do, like DanoT describes.