The situation for D* with regards to Red Zone is different. E* is going to offer RZC cheaply in order to persuade some of their customers to not switch to D* to get ST. They know they can't attract avid NFL fans with just RZC, but it is an inexpensive way to keep some of them.
D* has to be careful in their offering of RZC in that they have to protect the ST revenue stream. They do not want their own subs to drop ST in favor of RZC. I'm sure they'd like to protect their customer base that might switch to E* in part due to the availability of RZC, but I suspect the data shows that this isn't a large number.
They have to be data driven on these types of decisions. If they have evidence that indicates they will gain $2M in revenue from increased general subscriptions due to offering a cheap path to Red Zone, but that they will in turn lose $4M in ST revenue, then there isn't much reason for them to do that, even if it does irritate some of their customers. And if they feel they can placate some of those irritated customers with a secret deal, then that may well be their most logical decision.
However if general demand for the RZC grows to the point of where it does begin to drive more customers to their competitors and the overall impact on the bottom line from that exceeds the estimated loss in ST revenue, then they would likely reconsider their strategy.
I don't know how good their market research is, or how shrewd they are in making these decisions. But I can understand why they would choose to not offer RZC right now in a way that is competitive to what E* is doing.