According to Great Planes it is not as simple as tossing the ARF parts in a box and calling it a kit.
The way it has been described, each worker in an ARF factory only builds a specific assembly.
They do not have plans to work from or build manuals.
They have fixtures to line up the parts and use heat activated glues.

To make a kit, they'd have to print plans that we could use and write a manual.

Also, the ARF may be totally different than the kit. When the GP Skybolt was introduced as an ARF it was 1.5 pounds lighter than the kit. On a 60 size plane that is a huge difference and it means the ARF hasd a lot less wood in it than the kit.