I don't think satoshi is dead,  but rather he is playing smart,  someone that could build this kind of system should be smart enough to hide himself/herself or even themselves, working among us without anyone knowing it, my best guess is that one of the promoters of bitcoin in its early stage is part of the people who Built the project, Andreas antonopoulos also said that he chatted with satoshi over the email, don't you think he would be the one.