Why not indeed! I am not sure if the ends of the spools can be made thin enough in plastic to allow them to fit all cameras. It may not be a problem, but I have had some problems with 120 plastic spools in some old (made for 120) cameras. I don't recall offhand which cameras, or whose film it was - perhaps other than Kodak, Ilford or Fuji. I don't personally need a large number of any one type, but the idea has merit.

Cheers,
Clarence