DISH isn't that integrated with BB yet, it's still being worked on. ... New acquisitions take time to iron out. DISH has only owned BB a few months, and a lot of people are already asking for a large number of changes to how both companies do business. Give it some time (in corporate time that means at least 2 years).
That's a lousy excuse, in my opinion. Dish shouldn't have rolled out something half-baked. All these random things that they are throwing into Dish (multiple online system websites, conflicting ways to order movies online, this rental thing) show a lack of organization, confuses Dish customers and damages Dish Networks reputation.