When one PAYS for an RV site to put their RV in, there is a moral and possibly legal expectation that the site will not cause damage to one's vehicle and that everything promised (including clearance and length) is as advertised.
Paying for an RV site in an RV friendly park that can only be used if branches scratch your vehicle is insane. That's kind of like getting a hotel room with bed bugs, a broken heater or AC, or a toilet that doesn't flush and then being told that complaining is for selfish people. How about a hotel room with jagged metal on the door that rips your pants or suitcase as you enter. That sounds fun.
Trimming branches is good for both the trees and the RV's.