I've seen first hand the damage that has been done by the horseman and their steeds. Some parts of the trails I observed, especially the ones that cross creeks, stand out. There was as much damage to the creek beds, creek banks, plants, and trees, as if a dozen wild boar had just visited, rooting up the place. Not to mention people resting their horses in the larger streams during the warm months, presumably allowing them to drink, and urinate, and poop in the streams. I have found though, on many occasions, these were rather inexperienced people who had rented their horses at the liveries in the park. And I have seen my share of horseman's camps and I understand exactly what you are talking about. These rude practices could be minimized by people, but most just don't seem to care.
I really am wary of any management that includes deceit in their reasoning process, no matter what the subject. The whole idea of back country fees did not appeal to me in the least, not so much because of the money, but because of the hassle and future possibility of escalation into something more undesirable in the future.
-don't tell me why we can't, tell me how we can.- whitefeather
Blue skies, warm gentle winds, and trout filled waters to all!
(Wilu Sgis, Wami Tsenitli Winidis, Ani Tiwuti Wiledi Weitas Do Ali!)