There are budget and social constraints to these situations and the issue on leases and time shares is that they are in fact, a purchase.
The temporary nature of that purchase is reflected in the lease terms, but then so is the right or lack right to sublet and that's where access is either granted, denied, or disputed.
Retreats need certain resources that Mr Rawles implies but speaks around, and two assumptions come to mind, and dare I say it's the natural classism that an Army Intelligence officer is going to retain after service: reliable family members, and a family support level of income base. A.K.A middle class or better, which also goes to military pay structures which are anything but self sufficient or sustainable.
In the rest of the real world, you don't rate more pay because you got hitched and spawned kids, and then there is the issue of either strong personalities in the family who are not into prepping, or weak personalities who will go along but aren't really into it.
Kinda hard to meet those "family values" standards when you have only moderate wealth accumulation and income. For example, in the culture I come from, if you don't have family wealth and support, you don't get married. If you don't have family to support, you won't rate a healthy salary anywhere in that culture. Heck, my own mother ran a credit check on my dad before even agreeing to date him.
A really big factor on this is also reputation, and what stories come out of any of those places. Granted, the predatory groups can make plays on those bunkers, but rolling up those little cabin homesteads, there is not a valid simulation anywhere that shows those as very survivable in the face of a large scale attack. In fact, even small groups can get predatory with them. The common play though, is an adversarial whisper campaign around town, some local official types declare open season on the social outcast, and they get looted and exiled or killed. Don't forget, in the year after the destruction of the Branch Davidians, there were billboards put up supporting the BATF in Texas.
I found that in small town USA in my adult life, the smiles and handshakes last only as long as the padding in my wallet does.
One of the big issues with giving full ownership to shareholders in a retreat area is that they can then sell that to someone who is going to be predatory to the rest of the residents or a detriment in some other way. I have seen that in functionally Ungoverned parts of Northern California where meth lab operators upstream of pot farmers were dumping leftover chemicals. Then you have the dirt common local theif scavenger types, some of who are NOT the bottom of the local food chain. Imagine the nightmare stories when it's the tow truck / junkyard / chop shop operator who is the leader of the local motorcycle club and his brother is the Sheriff and his wife's best friend is married to the district attorney.
I recently rolled out to survey one of those "town for sale" situations in Tiller Oregon, and took lots of pictures, posted reports and opinions, and offered to coordinate Marke since there was interest in establishing it as a planned community. As it was, not too many people took my effort seriously, either on the wealthy side or the piss broke side. That said, personally, I scoped out a bunch of places and opportunities for bugout and relocate options.
That's where the "survival condo corporate management" and their hired security force of outside mercenaries needs to be available for play, and pooling resources to hire that is what makes economic sense. I know personally, providing safe, secure and reliable service to wealthy people who are willing to pay for it is a better bet for me than swearing oaths of mutual aid at the trailer park and expecting it to pay off when I actually need the help. Been there done that.
