Because it holds much better to heat and glazing the surface of the shoes and the needs of a 1/8 clutch is very different of a 200mm clutch. What works for a 1/8 doesn't need to work for a 200mm car.

Red shoe is great for some setups (In fact I've used it sometimes on 200mm) I use routinely a yellow shoe from Enetti (I haven't tested the yellow one - have one for testing, but need to do it).