Going back about 20 years ago here at TUG, there was discussion about what RCI's core business was. IIRC, I opined that RCI had plans to be much bigger than timesharing - their sights were on the vacation travel business, because that is a much bigger market than timeshare exchanges.
Timeshare exchange is just one piece in that puzzle. Their intent is to leverage every single part of their operation toward that end.
This is completely parallel with the operations of many club systems, in which they are increasingly providing opportunities for members to use points for more than just exchanges. I've even sat through presentations in which the sales person stated unambiguously that the company's goal was to be the first place that members went for all things related to travel - air fare, car rentals. cruises, hotels, resorts, tours and experiences.
Even if you focus solely on timeshare exchanges, there have been big changes since the DeHaans started RCI - namely the rise of trading opportunities inside resort systems. At the inception of RCI, exchange companies were the only way to trade from one resort to another. In time, resort operator recognized they could build internal trading systems and capture for themselves the exchange fees that were going to RCI. So the resort systems developed, first for internal trading, but now they look for ways to capture external trading activity.
So, if you were in a management position at RCI, one thing you would need to address is how do you respond to having your affiliated resorts taking bites out of your revenue streams. You can't kick them out, because you need their inventory. But if you don't respond somehow, you are consigning to having an ever shrinking share of the market, and eventually becoming irrelevant.
So, no timeshare exchange isn't RCI's core business any longer, From a business standpoint it can't be. They need to tap other markets, or they will slide into irrelevance.