Pac 12 regional channels

Why can't Comcast give us access to all the Pac 12 channels on the X1?   We get the national and our local one.    

Either directly through live TV or streaming through an X1 app.

Comcast lets us watch all 7 on Comcast's mobile app.   We can log into Pac 12 and watch all the channels as well.   

Just silly   X1 has all these mobile apps, but not a Pac 12 app.