I think the legacy is that Dish had gotten A LOT of calls to CSR's from frantic customers saying they have LOST several of the channels they pay for (I got 4 such calls from my family back then) only to learn that the customer had the guide on one of the custom lists. Believe me. This was a bigger problem than you may think. Since the default to My Channels, Charlie has probably seen his CSR phone costs go down at least a bit more than a bit.
I do propose that Dish should offer all the options we power users want, but bury them in layers of menus so that the common sub will probably never accidentally activate it because they just don't go there, but it would be available to enable or disable for us power users. I, too, prefer the guide to stay at what I last left it, and find the current default a PAIN. However, the default is BLISS for common customers I know who would panic that they can't get their favorite channels that they pay for.
The problem is that Dish often has to go with the common customer since they are the vast majority, but often at the expense of what Power Users would find a superior experience. Maybe they should have a menu option that says Advanced Users with a pop-up that states that "The following is for use ONLY by advanced users of Dish systems (tech weenies
) and you may inadvertent mess up your system. Leave these options to the Power Users. "
.