I'll spare you true breed jargon but supply some cold hard facts:
Pit bulls make up 6 percent of the dog population in Canada and the US, but they are responsible for 68 percent of dog attacks and 52 percent of dog-related deaths from 1982 to 2009, TIME Magazine reported.
This is the exact reason some insurance companies will not take a chance and allow them in the campground. Insurance companies care about reducing or eliminating risk, and paying out on claims. That is how they make their profit.
Of course, not EVERY pit is trouble. If you want to take a chance, carry a large insurance liability policy and go for it.
X2, I am not sure why some one would intentionally compromise and limit their plans to RV. If one wants to limit their RV experiences to Boondocking areas, then having a pit bull MIGHT make sense:(