I think full timing is just a name used by the motorhoming community. There have been people living full time in their motorhomes for years, and they have called themselves or been called many different names. Gypsies is a common term for most travellers but true Gypsies are an ethnic group that you are born or (rarely) marry into, Diddycoys were travellers that were not pure blood Gypsies and were somewhat down the pecking order and looked down upon by most.
Almost every country has its nomads and most have different names for them, many of our modern itinerants, aften called Pikeys, Gypo's, or New Age Travellers suffer a terrible reputation as law breakers and being a social nightmare, often moving onto areas of land, private or public, and leaving behind a terrible unhygenic mess. It is often said that crime rates rise considerably in the areas that these travellers frequent.
"Full timers" whether working or on a full time holiday, may live full time in a motorhome but that is about the only similarity to the above mentioned. Fulltimers will mostly pay to park, although there are many that predominantly wildcamp, their vehicles will be taxed and insured, they will leave a place tidier than they found it and they are always considerate to the local population and they do not rely on the proceeds of crime to live.
I will be "full timing" later this year, the cost of scrap metal is going through the roof, so the wire stripping should be very profitable.