I think you are correct, can't see buying that many timeshares... probably a combination of both. That said, we are starting to experience what you are saying... seems like most of the well rated places are tough to get. I think one of our biggest eye openers is that there really isn't much available (we though it would be the opposite. Are people now just renting out their TS themselves and bypassing the RCI and II option? Thanks again for responding.
The quality timeshares were booked out a year or more in advance. What you see as last-minute stuff is the last of the leftovers. If you don't care where you stay, then you may find "something" to book. If you want a specific resort or season, you MUST plan ahead.
It isn't that their availability has gone away, it's all about the timing. But yes - some owners do rent theirs out, to recover their maintenance fees, and perhaps earn a little more. There are a number of exchange companies, so the deposit you are looking for may have been deposited to a different company. By the time someone opts to deposit to an exchange company, it's because they don't want to hassle with doing something else.
You need to understand how exchanging works. Go with me here: In a perfect world, someone deposits their time to your exchange company, and that time becomes available for someone else (you) to book. You select that deposit, pay your fees, and you take your vacation. But exchange companies have Ongoing Searches available, where a member can request in advance an exchange to a certain resort or whatever - when one becomes available. So IF that first person deposits the week or whatever that is exactly what YOU want, and there are NO ONGOING SEARCHES on file against it, then that time becomes something you might see as being available, and you can book it as mentioned previously. But if there is an Ongoing Search, it snags that deposit before it ever makes it to the public inventory. You'd never see it.
If it does happen to make it to the public inventory, you must be the first one to see it and grab it right that second, before one of the tens of thousands of other members who are also online and searching when you are snags it before you see it. So it's a very, very unpredictable, crapshoot situation. You simply cannot count on it ever being available. Caveat emptor.
The latest mantra of timesharing is to "own where you want to vacation." Owning in a hotel or mini system that offers internal booking options to the locations you want to book will go a long way toward getting you into what you want. Those tend to cost more, particularly to get to that 16 weeks a year goal you have. Even booking those last minute discounted times someplace will cost you investment money to have enough credits, points, or weeks available to book or exchange. You need to factor in the overhead to support such a plan, and how much you'd have to pay to make those exchanges and such.
I'd suggest you try renting timeshares from existing owners that will take you where you want to go, and try it out. You may learn insider secrets that will convince you to either opt-in fully, or go a different way. Another option that has been mentioned would be to try a multi-week vacation rental, rather than a timeshare. A lot of people with vacation homes like to rent them out when the owners aren't staying there.
Dave