I am one of those RV drivers that you all are cursing out and I'm going to tell you my side of the story. I drive many two lane roads in the mountains that do have pull-outs for slower vehicles. Very few of them are paved. When I start to see a line of cars behind me I start to look for a way to let them by. At the moment that I see a pull-out I have only a few seconds to be sure that it is wide enough, long enough, level enough and the surface is stable enough to make it safe for my RV and my family to drive onto it and drive out of it. If I am not sure of our safety I will pass it by, and you in the line behind me will throw a fit. But the safety of my family and the people in the cars behind me comes first.
JMHO.