In reply to Offwidth:
I deliberately avoided talking too much about culpability for the erosion, because like I did say, even a fairly efficient ascent contributes something.
I agree that an efficient clean aid ascent is basically no more damaging than a free ascent - I guess you always weight the cams, but if done smoothly it probably makes little difference. We were almost caught on the headwall by an Italian team who were fast-frenching the route in a day - no etriers or anything, just plug and pull. I think quite a lot of American climbers do properly redpoint-siege the route, which is almost certainly worse, but it's hard to say they shouldn't without sounding elitist.
The bigger problem is haul bags - hauling has made a right scratched-up mess of some of the walls, and run deep sandy grooves into the finishing slabs. Having shared the ledge with an aid team for a night and watched their process, I was left thinking it all seemed more like labour than climbing, and that if people want to enjoy the positions of the buttress, it would be better for both the rock and them if they just walked around to Angel's Landing and abseiled it! Regardless of erosion, our tactic of depositing a haul bag on the ledge from the top the day before climbing is one I would recommend - save all that hauling energy for jamming.
P.S. if you ever do the rest of the route your abiding memory won't be how much of a sandpit that first pitch is
Post edited at 11:25