Now realistically forget the 'ever made' part, and focus on classics + all recent content, there's no reason why cable companies shouldn't be able to deliver this soon. Merge the on demand libraries with streaming video sites like Hulu, and we're almost there already.
And yet both hate to share profits, additionally the content owner are still trying to find out what price the markets will bare.
To do that they start high and slowly work their way down. And that slows down adoption.
Actually I think with record producers, video content owners & to an extent, publishing giants are all in a similar (leaky) boat. They are in a situation where life has been good, they are on top of the world. Only way to go is down.
Any move in the directions that technology is pushing towards like better, wider distribution, reduced production costs & power to the consumer is troubling. For one thing, they have a better hold on the here & now then the long tail. Sure they own most of it, but better distribution opens the doors to a groundswell of small producers. Expensive special effects, 1000 actor scenes, are no longer as big a differentiator. Now you want to give these $100k budget jokers access to living rooms?
Will better distribution make people watch more TV? probably not. Why take a chance?
Supplemented with Easynews and basically you can get anything you like on-demand.
On demand is lean forward with the viewer having to think and decide explicitly what they wish to watch.
With TV you can lean back, not think too much and watch whatever the channel has chosen for you tonight.