I think Satoshi's plan from very beginnign was to create the biggest pyramide game the World ever saw: bitcoin. And the reason to do so was because he wanted to be the Worlds richest man one day. And he realized best way to grow Bitcoin while still holding a big enough part to be come super rich one day is to mysteriously disapear and not touch his coins for years, maybe for 10 years. I would guess he locked his coins somehow so he can not touch them even he wants to. Especially can you all imagine how bitcoi price would suddenly go down if he reappears suddenly and starts to sell off his 1 million bitcoins? Better he stays hidden until his goal of Worlds richest man is archieved...