Why is the Xbox One "Family Sharing" ability being ignored?

So part of the Xbox One story is the ability to define your family (up to 10 people) and allow them to play your library of games from anywhere.

This is a huge benefit. My family will be spread across at least 3 states and at least 3 consoles. We can purchase 1 copy of the game and all play that one licensed copy of the game (although it appears not at the same time).

This pops up in threads, but is largely ignored.