TV is for entertainment as far as I am concerned.
It is capable to air programming that is instructional in nature that when viewed results in learning of some capacity.
But, I would venture to say that an educaton based solely on educational TV shows is hardly complete.
It's all about money. The more money a producer has, the sexier they can make their shows, whether educational or not. From what I can tell, most educational shows, especially kids shows, appear to be developed on a limited budget.
I have not viewed television with any regularity in over 15 years, and I intend to keep it that way. My kids watch videos of stuff my wife and I are cool with on our TV + DVD player. They watch it when we want them to, not when it comes on the air. The rest of the time they are playing, reading, drawing, making things with Legos, helping me do shores (baking, sweeping, etc.) and playing outside with us ala riding bicycles or kicking a soccer ball or playing catch. My kids are smart and speak better than almost all of their peers, and even better than kids older than them. They didn't get that way by being TV zombies.
I like a good documentary now and again, but more often I buy magazines to stay current on world events, science, art, etc.