Xfinity Stream- Out of home

Why are so many channels not available when using the Xfinity Stream app away from home? 

Other streaming services, like DirecTV and YouTube TV, have all the subscribed channels available no matter where you are, at home or away. 

The excuse given in the Xfinity Stream app is that it’s a contractual issue. How is it that all the other streaming services can figure this out but not Xfinity?