I can only guess from the few clues that we've seen on the forum. My guess is that ARFs are not built at all like we build kits. I know ARFs aren't built on the plans, like kits are. I would guess that means that a lot of jigs are used, jigs that a kit builder wouldn't have. That means that a lot of ARFs just can't be made into a kit that the average modeler would have a chance of putting together successfully. As a result, I think you'll see more and more planes offered as ARF's, but not kits.

I could be wrong, these are just guesses. It may simply be that certain businessmen aren't into the kit business, which is their right.