I cannot express how strongly I am against this. The first rule of most every outdoor activity is "take only pictures, leave only footprints". That applies for everything from scuba diving to mountaineering. Hammering in rods and installing ladders on otherwise perfectly climbable rocks is just wrong. There is a time and place for fixed protection, and regular climbers have huge debates about this, but installing ladders so people can more easily "climb" in hiking boots doesn't meet anyone's standard. I've known many climbers who, if seeing any of this, would actively destroy such installations if anywhere close to existing routes. And in Zion? I guess it isn't halfdome or dawn wall but this is still a climbing mecca that that should be left unaltered.
I was once at a very popular toproping area when an army unit of about eight people showed up. They were about to hammer pitons into the cracks to "practice". The word when quickly around the crag and they were basically run out of town by a hundred climbers. You don't damage rock casually, not established climbing routes.