In about 25 years of camping, we've stayed at many KOAs (NJ/Fl/Az) using I-95, I-10, I-20, I-40...and have come across some that are better than others, but never a "dump". That can also be said for non-KOAs on the road.
Using the Trailer Life Directory, most of the time, the ratings are pretty good. Once, however, a 8/8/8 turned out to be, in our opinion, a 2/2/2...but on the other hand, a 4/4/4 rated cg turned out to be one of the most unique places we've ever stayed at. (I guess the 4/4/4 place didn't take the raters out to dinner or something......)
As far as SOREN says (above) that KOA will divide it's places into 3 tiers (excellent, fair, poor)?? (I've never heard this) I wonder how they might describe the "poor" places. Things like "stay at your own risk"? "Bring your own bottled water?"
Yes...franchise $$ is important...but reputaion is more important, IMO. If some KOAs are "dumps", KOA should dump them.
Them "dumps" are what I really wanted to see when "Undercover Boss" went with KOA. But all this guy did was visit the very top-of-the-line and not too far from his home office. Accomplished nothing for the betterment of his company.