Great timing for this question.
I just switched from Dish network to DirecTV. Reason??? I, like you, prefer the educational/informational programming over the mind numbing sports religion. Ever since Discovery Channel diversified into several channels, both TLC and Discovery have been but a shadow of what they used to be. I eventually got fed up, and compared Dish Network to DirecTV in the channel lineups. In order to get the complete Discovery networks (sans HD,) you have to buy the top 180 programming package.
You can get the complete network breakdown (sans HD), at DirecTV's entry level @ ($45.99/mo) vs. ($52.99) for dish's top tier. There's still alot of crap channels I don't want, but at least I'm not being forced into the most expensive package for even more crap channels that I don't want.
I still love the excuse I got from the Dish Network rep when I called and cancelled. I was asked why I had switched. When I told him that I wanted the rest of the educational stuff without the junk, he flat out told me that if they offered that, they'd lose money.