I can understand this "10-year rule" to some extent. I recently stayed at a park where there were some really ratty permanent residents. The trailers looked as though they were falling apart, and the residents had screaming kids that wouldn't stay away from my campground area. I never came up missing anything but felt like I was being "cased" several times. I've been in this campground before and it has gone downhill since these few trailers have moved in. One of them was there 3 years ago when I was there last. I don't go camping to put up with those kinds of things... If I ever owned an RV park, I'd just implement a 3-month maximum stay time. It would be by contract, only... so I could evict the squatters if necessary.
J & D in Lovely Weatherford, TX
2016 Jayco White Hawk 28DSBH TT
2014 Ram 2500 Crew Cab 4X4 6.7L Cummins