It's a pretty standard rule at any resort that doesn't have (or more likely can't afford) the proper insurance to allow inverts. I'm not entirely sure how it works as far as from a legal standpoint, my understanding is that it's a resort rule not a law, but Pennsylvania could be completely different.
Sure it sucks, but it only takes one asshole to fuck himself up and RUIN everyones fun at one resort (Does the RCR resort incident ring a bell?). Sure places like Keystone, Breck, Whistler, etc... have this insurance and let if fly because the parks are properly maintained, patrolled, and the level of talent is there, your average gaper isn't going to jump into the Breck park and try backflips on one of their jumps. Resorts in PA... the vibe, jumps, and bascially everything about the places there are completely different and they know it, so why let it happen? It would definitely correlate to more injuries in the long run if they let it happen.
It's not a "stupid" rule. Sure it's lame, weak, or one of many other adjectives you could use to describe it as less than desirable, but definitely not stupid It makes sense to anyone who has a brain.. But wouldn't you be more pissed because your mountain went out of business because if frivilous lawsuits when some fuckstick breaks his neck trying a flip?
NS has become even more increasingly ignorant on how the way the industry works recently, it's becoming almost annoying to come on here and read some of this crap. Ya, sure it sucks, but unfortunately life isn't always going to be fair and allow you kids to do whatever the fuck you want. Figuring that out sooner rather than later is the biggest life lesson you can hope to learn.
And saying it "only affects you" if you get hurt is soooo incredibly IGNORANT! What about your parents, the ski patrol, friends, and others who want to hit the park but it's closed because you're hurt. Or have to now help you wipe your ass because you broke your neck trying a flip and can no longer walk? It MOST CERTAINLY affects others. Skiing isn't a team sport, but if you fuck yourself up good trying flips, it changes a lot of lives other than just yours. Please understand that.
I can't believe the ignorance coming from that statement. I've seen a few head injuries in my life and have come to understand this rule and respect the mountains that wish to enforce it. Please grow the fuck up and step outside of your ignorant "let me do what I want" mentality for one second. If you want to try one, go to a mountain that lets it fly and have fun. Hate me, give me some shitt karma, but once you grow up and see a few injuries up front, you're tone will change. I guarantee you.