It's a company policy. If we could get exceptions, I'd be submitting them everyday. We have a lot of customers who want to sign up but can't because they don't qualify. They don't qualify because the promotion requires a credit card. I personally agree that there is a better way to determine a whether a customer is going to be a good customer, but this just happens to be how they are doing it now.
It weeds out a lot of the customers who have been causing them negative subscriber acquisition numbers due to disconnects, but it unfortunately also excludes a few would-be good customers from signing up as well. Customers who don't have a credit card also have one less source to tap into if they run up PPV or other expensive programming and don't have the money to pay the bill.
Really, at this point, if you can qualify for a no-fee credit card, get one. Use it to sign up for DISH, then cancel it, or never use it. If you keep it active and only put maybe a tank of gas on it then pay it off, in time it will actually help your credit score. It would be a paid off account with a history. Then when anything else like this comes up in the future, you're set. If you can't qualify for a credit card, then DISH would probably be right in not approving the application for DHA. Unfortunately, this is getting to be a credit score driven world. Ask anyone who has recently moved. Every new utility and service requires a good credit score to get new service without paying a large sum up front.