Like it or not, experience has taught us that long term stays are not compatible with how we want to operate our parks. Old Biscuit's triage of the three types of full timers was spot on. The full timers who travel constantly fit our customer profile. The arrive, go about their business, and when they feel the need to move on, they do.
The seasonal guest can be broken down into two categories. The first is those people who travel constantly, but want to stay in one area for several months. These seasonals generally are interested in a highly discounted rate, which we do not offer. In snowbird areas, another poster is correct that they often tend to develop closed social groups and are unwelcoming or, at the least, indifferent to, short term guests. The second seasonal guest is the one who has a site close to their city residence and they use the site as a weekend getaway. These parks tend to be concentrated in the Eastern and Central US. Those parks often have large amounts of amenities and activities aimed at attracting those customers. I have no first hand experience with that type of park.
Old Biscuit's third group is the residential occupant. These are problematic in that they have a different mindset from the vacationing guest. They are usually pounding out a living. Clutter, rig decay and outright disdain for the vacationer is evident with many of these residents. The clutter is easily explained in that these residents have no need to cull their possessions, since they never have to pack up and move. Rig decay is also easy to understand, the rigs never move, they don't take them to the wash, the sun always shines on the same spots, and inertia and complacency sets in. These residents also have a different perspective on their environment. Travelers are excited to be there. There are new things to see and do. For residents it is old hat. What travelers see as wonderful, the residents may see as a pain in the neck. Heck, I see it in myself. When elk or deer descend upon the park, guests see a fabulous photo opportunity, I see elk and deer scat to clean, and flowers and trees that are going to be damaged by hungry vermin.
And on a business note, the residential aspect of an RV park can become a target of local government. Residential usage of an RV park raises concerns regarding schools, taxes, social services etc. Parks that have a large number of permanent residents are not good for the industry as a whole.