The short answer is: the owners of the holding company.
"Holding Company" is a very common name. It is almost the "Default" name in a situation like this.
our firm has two pieces that operate, and a "holding Company" that is the sole shareholder in the operating companies. The partners own the Holding company, not the operating units. Sears is set up the same way with Sears Holding owning both Sears and Kmart.
It does make it easier to sell one of the operating units, although there are a lot of other reasons for setting things up that way. Among other reasons, it limits liability if one of the operating units is sued. It can shield one from the liability of the other.
There also could be financial reasons in the way of the kinds of loans that one company takes out. For example, A stand-alone satellite company would be very capital intensive: They spend big bucks to launch a satellite and then they take in payments over a long time to make the money back.
A stand alone Dish Network, no so much. They take in cash every month and would make payments to programmers and the Satellite provider on the same basis. If it were separate, almost none of its costs would be capital.
This would probably almost immediately increase the valuation of both entities, I would think.
Another advantage would be that you would thik Dish competitors would be more likely to buy things from Echostar if the two companies were separate. Settop boxes, in particular. Why would Comcast make it's own boxes when they could by them? Now they won't because Dish is a competitor.
This has happened in the auto industry. Delco used to be owned by GM. At that time they did some business with other automakers, but not much. Now that they are separate from GM, they do a lot more, although most of their business is still with GM.
Also, it would make it easier to start a new DBS service. Echostar could almost make it turnkey.
This is getting more interesting.