There's a little difference between not being in F1 and being in F1 and not winning......
If you go to any GP anywhere in the world you will see more Ferrari flags and supporters than probably all other teams combined and I'd say McLaren would be easily the 2nd most supported F1 team. I think if Ferrari and McLaren were to pull out of F1, it would cripple F1 from a spectator point of view and probably also take the 'pinnacle' out of the sport. Some history and tradition cannot be f**ked with....