I don't see how this is worst than Sony giving away games to PS+ members.
Also, if a game is rented, doesn't that game can be rented like a thousand times while now it would be shared to only ten people.
Owner of the game can always play his game and he can play the game online with only one of his family member at a time. Once the shared copy is being played by a family member, other members can't play the shared game. It's not complicated at all...
I believe there will be some kind of catch though. Since you can share the game with ten family members but you can also "give" the game to someone from your friend list if he's been your friend for at least 30 days and get access to all the games's features... this is where lies the catch I believe.
Since you can give the game and access all features, that means shared games will lack features. I mean, maybe you can share COD with a family member but that shared game can't do much more than single player. Only the owner of the game can invite you to a multiplayer session. Also maybe the single player part of the shared game does not have all features like achievements, different difficulty levels etc...
Just a thought
