Because I can give the credentials to someone who want’s to play the game and I don’t give access to all of my games.
I even do that with games I buy. You hacked my diablo3 account? Bad luck. But you don’t have access to all my other games. I can even resell the whole game account when I’m done playing.
Don’t get why my inital post was downvoted. I’m not saying that you should do that. Was just asking. But ok.