I'd agree John - I think all National Park Authorites need some more teeth or at least more balls. It is their definition of National Park Values, and indeed the general public's definition that comes under the spotlight in matters like this or the speed limit on Windermere (an example I think of where the value of a 'special' place has been upheld against those who simply see National Parks as playgrounds.
I have a reaction to via ferrata similar to that when I saw various wooden 'steps' nailed to a favourite tree when I was a kid, to allow many other kids to climb the tree, rather than using what nature provided. As a kid that turned an adventure with nature (and a lovely tree) into a playground toy. However I haven't seen this or other via ferrata nor used them and so my view of them is somewhat superficial I have to say.
I think perhaps our approach to the natural (or at least wilder) landscape needs some adjustment (as a population). Perhaps we need to instill some sense of respect for our landscape and its life, both wild and farmed.