Pseudonymous addresses and no address re-use is cool, but it's clearly not good enough for real privacy. If Satoshi could figure out a good-enough solution to the Byzantine Generals' Problem by creating the blockchain, couldn't he figure out coinjoin? It's curious that a person who was obsessed with privacy didn't implement it at the protocol level. Was he in a rush to release bitcoin? Doubtful. Was it above his abilities? Doubtful.