Im not sure if you've ever touched your caliper or rotor after a moto or a ride, but they are hot. Metal expands when it gets hot and with a design of a wave on the exterior and on the inside, allow it to get hot and when it cools down, stay flat. Thus never/taking longer to warp/ware out.
Also, saving a bit of weight can help with rotational mass and letting you brake later giving you an advantage over someone who is using a typical rotor setup.
