This is nothing new. If you take a look back at the history of the executives, and larger share holders (Ralcorp), they have a history of selling. All except for Adam Aron. Adam Aron was usually the one executive who hung on to his stock. He only sold his when they were about to expire.
As for why the Jeff Jones, Roger McCarthy, Bill Jensen, John Garnsey, Blaise Carig, etc do not keep their stock is anybodies guess. Maybe they need the extra cash to live the life style that they are living, in the area they are living. Beaver Creek, Vail, Keystone, Breckenridge aren't exactly cheap places to live. Although Summit County is cheaper than Eagle County.
As for the product, as long as the snow keeps falling the resorts will continue to make money. Plus, with the relatively low debt and the open lines of credit that they have secured in the last couple of years, along with the high cash flows, the business is good. (All of this information is readily available from any press release.)
Maybe. I just would have thought that the officers would hold on to their stock because they would be convinced that share price would be going up based on the positive performance of the company that they are responsible for. Why would an investor want to invest in a company that the officers don't (or so it would appear) believe in?