I'm pretty sure that Northstar isn't a public mountain as such, it might be on public land, I don't know, but it's owned and run by a PRIVATE company. This means that if you have the money or the power, you can shut it down for personal use. What you also seem to miss is that this is a smart move by Northstar, they get shit loads of exposure from letting Shaun ride, and make thousands of weekend warriors wet their pants to go ride at "that mountain Shaun White had shut down".
And like Buttmilk, or whatever his name is, said, your beef shouldn't be with Shaun, but with the system that allows and uses such strategies.
Come back when you've had a long think about your arguments, they don't make sense.