I don't think too many parallels should be drawn between skiing and "most legitimate sports" regulation-wise. Yes, in sports where several athletes are on a track, field or court at the same time there are rules that prevent them from hurting each other. Still, there aren't that many rules in the "big" legitimate sports that limit the athlete's opportunities to showcase his or her skill, are there?
A hockey player can shoot the puck as hard as he likes, even if it might hurt an opponent who gets in the way of the shot. A downhill racer can go as fast as he can, even if the risk of getting hurt increases with velocity. A ski jumper is free to jump as far as he wishes, the only limit being the size of the hill the contest is held at.
I know aerials has strict regulations, but as a sport it doesn't value the same things as slopestyle. Aerials is all about execution of predetermined tricks, while in a slope comp you'll be rewarded for being creative and coming up with new stuff in addition to execution. You can't do that if there's a limit on the amount of spins you're allowed to do.
The sport is evolving, but I doubt that its fundamental idea will change.