Family Sharing - Using one Payment Card

As your family could be made of up adults not just one adult and kids... the fact you cannot hide or avoid being forced to share 'one' set of payment details is short sighted and limiting. Why is this set-up like this and is this ever likely to change? We want to be able to share our Apple TV / iTunes movies and tv shows - as purchased 'from' Apple cross the family but we can't do this unless the one person setting up the family share gives full access to their payment card for all purchases. this is ridiculous no?? Can anyone shed light on this so I understand.