There are no perfect plans
Alan has it correct and if that was the whole story RTU might even be a great way to utilize timeshares. But, as always seem to occur in the timeshare world, things aren't done as you'd expect. Most (not all) RTU resorts/systems aren't run by the "owners" (actually long term lease holders with the obligation to pay the fees) but by the original developer. Guess what? They want to make money. So rather than hold down costs and run thing as the owners would prefer they are the lord and master of the operations. Fees are what they want them to be and the lease holders are obligated to pay. Plus they can control things like week/unit assignments, trades, etc. The "owners" have no say but have to pay the bills.
And when it all ends I have to think the temptation will be to have the resorts in perfect shape. Why not? The lease holders pay and, of course, will argue that they expect a nice place through that last year. But if it really is well maintained and upgraded then when that 30th year (or however long the RTU term is) they should have a near perfect resort to resell and at ZERO cost to them! Does anyone think the fees will be reduced as the end nears? They should be but I'll take any bet they won't.
And what about resale (if it's even allowed)? Is a week good for 12 more years worth what one worth 30 or 40 years was? Of course not. So a depressed market is driven even lower by the limited use inherent to a RTU.
Overall its far from perfect but then again neither is deeded ownership. With that there are questions about what will happen when an old resort is truly past it's useful life. How will it be shutdown - who will still want to buy in? What if fees go nuts or too many owners defualt? There is no perfect timeshare (or house or condo for that matter). RTU, deeded, lease to own - you pick what you think is best and hopefully get your value out
RTU is just another way to have rights to a week "in paradise" of your choosing.