There would have to be some level of software support on Dish's side (in the receiver(s)) in order to implement this. I've no doubt that the chipset and it's firmware handles both ATSC and QAM but device the tuner is being used in has to know what to do with this data.Pretty much all of the existing USB tuners are ATSC/QAM so the chipsets are readily available so what extra money?
How many satellite customers also have cable service in their homes ? More importantly, remember that the number of Dish customers who want options, be it ATSC or QAM, on top of their satellite service is very small.I assume there are others in areas where OTA is difficult to recieve.