What might be a major down check(s)for some owners could be a weekend project(s) for others. My coach was built by one of if not the favorite builder to bash, Thor, and I have had no problems with it that I would bother to write a rant over. Reworked roof seals, repaired delamination, rebuilt the steps mechanics, reconfigured the electrical, replaced the starter for the generator, repaired a slide roller, replaced the toilet, repaired the engine throttle servo motor,,, all work I did myself. If I had to pay the $100 an hour shop labor for the problems and maintenance I might be more in agreement with the OP.
I feel each coach and builder should be judge individually, particularly when concerning a used. New rigs are going to have problems and the post sale support by the dealer and OEM will have a very strong effect on owner's opinion of the same.