If all LNT amounted to was that people didn't litter and didn't tear up the woods where they make camp, that would be great. Unfortunately, this seemingly modest ideal is nowhere near reality in many places. What's the point of arguing about TP when Billy Bob, Mary Jo, Jimmy Dean, and their 10 chilluns are just going to drive their 4-wheelers in to your favorite camping site and turn it into a shooting range, leaving one of their 4-wheelers, the target at which they were shooting, there to rust, since after all, everybody knows that a shot-up 4-wheeler don't drive good 'nemore. The only places I have seen toilet paper, actually SEEN it, has been in desert environments, in various canyons in AZ, near the most heavily used camping sites in those canyons.
I think the only thing I'd actually preach to backpackers about (as I step up onto my soapbox) is leaving stone fire rings at your campsite. They do nothing but attract all types of campers to that exact same campsite year-after-year. Glass, metal, food, and upholstery litter accumulates (yes upholstery.. I have no idea how or why they get those couch cushions into 9,000' alpine meadows, but they can and do); the sticks and rotting logs on the forest floor providing habitat for insects and other animals decreases as people burn it up, thus altering the ecosystem; trees get damaged as campers carve their names in them, hang things from them, tear branches off of them for firewood, and even cut them down to burn. Also, if the campsite happens to be at a scenic site (of course they usually are), then all that will happen is the scenic site will gradually get more and more trashed.
Of course, all these things happen at all campsites anyway when certain people go camping, but by leaving a fire ring, you just invited them all to camp at the same spot for years and years to come. Just scatter your fire rings in the morning. It's literally no harder than that. Takes 20 seconds.