Almost all doomsday, end of the world, etc. books from Alas Babylon published in 1959 have chapters or story lines on the impact of small towns threatened by overwhelming numbers of people fleeing to the wide open spaces.
There simply are not enough truly open, isolated places for everyone, and I'm sure most RVs are not setup for more than a few days not hooked to utilities. Even if they are, most don't have the storage capacity for supplies much longer than that.
With an 8 cu ft small RV fridge, four kids will go through more milk than it can hold quickly.
Everyone needs to buy food. Can you carry two weeks worth of food? Not need to go to a store for fresh milk or bread? DW certainly can't live that way.
That's what has cities like Moab worried about. Not the people out along the river in the BLM approved campgrounds. (There is no open dispersed isolated camping allowed in the Moab area.)
Moab knows those visitors will be in town almost every day, in restaurants, in the grocery stores, in crowds renting ATVs and such.
They also know that most of those places are not staffed this time of year, supplies may not be on hand for the purchases the visitors will make.
Even hiking in Arches, there is seldom a time you are alone, not with many other people close.
Yes, can't fix stupid, not even with duct tape.
