My point is that it's a spectrum, not a bright line. We do, in fact, have roads that go into parks. Some parks even have trails; some even provide bathrooms and campsites, with varying degrees of amenities. All of these things increase accessibility at the expense of the nature and wilderness of an area, so it's important to have lots of diversity in degree of hardening: does every waterfall need an ADA ramp? Probably not; should no waterfall in the world have an ADA ramp? No, that's needlessly cruel to disabled folks who deserve reasonable access to natural beauty.

There should be (and are) sites of natural beauty you can take pubic transit to, drive to, roll to, bike to, ski to, hike to, climb to, ice climb to, and yes, even cannot access at all, each category with it's own sub spectrum of difficulty (eg some one mile hikes, some weeks long treks). To me a via ferrata seems like the left hand side of this spectrum -- something in an already heavily impacted area that gives casual users access to something they otherwise wouldn't. If someone starts proposing putting them there they don't belong (real wilderness, serious climber spots) I'll be with you in advocating against that.