Unless these areas (or other areas in the NPS system for that matter) are within the boundaries of the Congressional designated Wilderness, they are not bound by the laws, prohibitions, and spirit of the 1964 Wilderness Act, nor do many of these areas have a wilderness management plan. Of course, the Wilderness Act didn't set forth use levels. One only has to visit several other wilderness areas across the NPS to realize during the summer, often we are really not alone in the wilderness.
As we saw with the 2006 NPS management policy fiasco, it is becoming increasingly easy for the NPS directorate to be handmaiden to the White House policy desires and not the Organic Act. Of course, one must only look at the rim of the Grand Canyon to see that development, tourism, and the NPS have always gone hand in hand.