I suspect the answer you will get from most F16 sailors is as follows.

"If we wanted to sail a fast, big, heavy, off the beach catamaran, supported by the large manufacturers the F18 is the obvious choice. F16 sailors generally prefer their boats slightly smaller, much lighter and just as fast. The fact that it isn't supported by the big manufacturers doesn't bother them, in fact i suspect some are actually happy that way. The cost of this attitude is that it will take longer for the fleet to grow compared to the F18 class, and that's ok too."

Actually I think growth of F16 fleets around the world is doing amazingly well, especially at your home club.

High performance cat sailing at our club has been revived because of the F16's.