That's a shame... but totally understandable if it's just not something she's into doing. It would be nice if she might sell to someone that would continue it as a bike park, but they'd likely be facing the same issues as Brad at Sterling Ranch.
I think the ATV/SxS crowd will likely continue to grow. They are perceived as being safer and requiring less skill to operate. You don't have to buy all the extra gear to ride in them. Many folks don't even use helmets. Also, they are not quite as focused in their use. The ATV/SxS's can be used for more than just trail riding. Heck, in many parts of Northern Arkansas, they are essentially the family vehicle! In many of the best motorcycle riding places like Moab, SW Colorado, etc,... the ATVs and SxSs are all over the place now!