Clearly it is the manager's job to determine what work schedule works best for each of their subordinates. They might have preferences but let's be honest, people can't be trusted to set their own schedules otherwise they'll work too hard!
It is a good manager's responsibility to maintain the health and longevity of his team. Obviously, that wasn't the case here, and the burnout superstar even left. Not surprising.
I think you're projecting your own personal biases and grievances into this scenario. I don't think it's a given that this was burnout related at all. You have no proof that it was, and yet you persist in treating it like a foregone conclusion.
I also think that you're wrong in making it the manager's job to police to work habits of their subordinates. I think a good manager should recognize signs of burnout in their subordinates and bring it up to try and address it, but you're arguing that the manager should impose their own idea of a healthy schedule on their subordinates rather than trusting them to know what works best for them. That strikes me as paternalistic.
Seen it all before. In practice, this doesn't work. You end up way too dependent on a superstar who is bound to burn out, and will take the whole team down with him.
That kind of thinking is along the lines of "just always pass Michael Jordan the ball". But that's not how healthy teams function. And it wasn't how Phil Jackson managed his team.
And you can credit John Carmack all you want. But his peak was when he worked alongside John Romero. Even Carmack himself has stated this. And Michael Abrash taught him the theory of how to do 3D rendering properly.
