You heard correctly that resale points can only be used to book DVC resorts. Be very careful if you decide to buy them and make sure you know all the restrictions.
You don't have to visit WDW every year with DVC points. I tend to go every other year or so and use my points for RCI,
DCL, ABD and Concierge hotels. Since I've joined DVC I have stayed at the following places using my points:
WDW numerous times, Aulani,
Disneyland, Grove Park Inn(NC), DCL cruises to Alaska, Western Caribbean, Mediterranean & Mexican Riviera and ABD Greek and Med add-on trips. I also have reservations for Las Vegas through RCI using my points.
I got a DVC membership to go everywhere that Disney went. Getting to go to WDW more frequently is just a perk. I know the discount in the cost of points sounds attractive, but you are severely limiting what you can do.