There is a real benefit of disk brakes on cyclocross because riding conditions can be downright cruddy contaminating the wheel rim and dramatically reducing braking power of calipers. Plus the contact patch is bigger on cyclocross tires where stronger braking can be utilized.
I do agree with you that it will be slow climb to acceptance on race bikes. I also believe in the context of road bikes, road disk brakes have a way to go in compactness, weight and development. There time may come in the future but believe it will be a while.