A lot of wilderness areas require camping 100 or even 200 feet from designated trails. Unfortunately, most places have no enforcement. In some places, especially river valleys with a lot of fire-killed or bark-beetle-killed trees, getting that far from the trail without camping under a "widow-maker" just isn't possible. I normally try to get a quarter-mile or more off trail just for the sake of privacy.

There was a recent thread on BackpackingLight about the amount of trash and TP "flowers" along the JMT. Sounds like a place I want to avoid! I agree that too many of these trails are hyped. Even the PCT is hyped even though at least in the Northwest it avoids a lot of the best scenery (maybe just as well). As a result, people rush from one end to the other, trying to finish in one season and missing all of the wonderful side trips they could be doing. Your mileage may vary, of course, but that hiking style is not my cup of tea!