I listened to that podcast back then, and I don't think that's quite true. He actually backed down a bit. Going from memory, while he did reiterate more hours = more accomplished, he also agreed that how many hours of productive work you can do in a week varies between people (I think the way he stated it was that most people will burn out doing crazy hours, so he admitted it's not sustainable). He said it's lesson he'd learnt at some point but because he's immune to burn out and has an insane work ethic it's something he didn't understand back when he pushed John Romero out of id for not working hard enough.