Main reason? All the sports channels you just named cost extra. You cant compare national HD offerings and then throw in PPV packages in with them and call it equal.
I'm not calling it equal, I'm calling it advantage to D*.
If you can get the same 50, 75, or 100 national HD channels on both, with the possible exception of VOOM (which will be less valuable as other channels come on line), and D* is offering several additional/optional sports packages, then D* will be seen by most as having a better channel lineup.
All other things being equal, if you poll the average family and tell them that they have a choice of having VOOM or the option of getting the NFL, NCAA football, NCAA basketball, or Major League Baseball, most are not going to pick VOOM.
I feel that E* is playing a dangerous short-term game in that they are riding on what could very likely be a short-term advantage in HD channels and are not out there competing for millions of sports fans.
I can see them not trying to outbid the ridiculous bid that D* put in for NFL:ST. I can partially understand not signing up for the MLB:SI contract. But if they don't bother picking up large regional NCAA networks, that many of their competitors are taking, then they start to look like a niche provider.