I really couldn't see the issue when flying over after staying at Rawnsley. You'd have to be a bit of an idiot to mess it up there in a 172, but they are out there, and fair enough, their perogative.
Light aircraft prang at Wilpena Pound
That thread should go some way to explaining it. It's only the most recent example and no doubt there would be far more like it if Wilpena was open slather to all. Worst part is that as soon as anyone hears "Wilpena" and "aircraft crash" the immediate assumption is that it's one of the scenic operators (see the first post in my link above) Not good for business that's for sure!