That's great until a game designer discovers that grief chases away the majority of players, and the griefers themselves will leave if they have no one to grief

That's great until a game designer discovers that grief chases away the majority of players, and the griefers themselves will leave if they have no one to grief. So from a philosophical perspective sure you're right. But from a dollars and cents perspective it's just good business to find ways to legislate griefing out of games. And that's why the market moved the direction it did.