In the case of D* and E* look at it this way; it IS digital from them to you.
You must know they are companies that mearly rebroadcast to you via their service.
They get a vast majority of their signals off of huge C-band and Ku-band satellites (analog as well as digital) just like you & I could directly.
Remember BUD? I still use mine. It still offers the best sound and picture, even the analog is better than DBS and cable and much cheaper subscriptions, BUT, it is not user friendly, it is expensive to startup, so companies gave up on their R&D and promotion of them because of these facts, thus it is dying for the END user. It is still the method of choice for the broadcaster, your cable and DBS companies.
OK, (the ultra simple speak) after they pull it off of the analog C-band, they compress it (now they call it DIGITAL) to make it smaller in size, add their security scheme and coding, and beam it to their satellite so they can direct it back to your DBS dish and IRD for decoding.
They are now the middle-man. They took a great, cheap product you & I could get ourselves, made a user friendly device and application to receive it, and are selling it to us at their markup prices.
This is all they have done.
Now that they have effectivly killed the BUD, they gear up to add more and more satellite locations, and keep pushing bigger dishes and more add-ons to get them. And trust me when I say they will place just enough services on each bird to "force" you to need the new gear.