So, possible scenarios:
1. Satoshi is a group of people. Subscenario 1: Founded by some powerful entity, to create an experiment or destroy banking system. Or make drug trafficking easier.
2. Satoshi is dead. He didn't really knew that bitcoin might have such success, he died before seeing it growing so much and that's all.
Subcenario 1: Satoshi was killed because of Bitcoin.
3. Satoshi is affraid of Bitcoin and how it turned up.
4. Satoshi is a person that has no life other than programming (21.000.000% nerd) and he creates things under different identities. Maybe was behind Napster too.
5. Satoshi is ET or AI or GOD or S8TN
You forgot the sub-sub scenarious, the braching scenarious, alternate scenarios, and possible mixed, merged, and parralel scenarios. The Satoshi conspiracy theories never end and never get tired. Someone always comes up with a new one. One day there will be a tv series just focusing on satoshi conspiracy theories.
Satoshi is everywhere and nowhere.
Satoshi could be all of us, or none of us.
Satoshi came from nowhere and dissappeared to nowhere, but his coins are everywhere.
Satoshi has no past, no future, and no present, but his creation is immortal.
Satoshi is an idea. Satoshi has inspired all of us. Satoshi is a legend.
Satoshi Nakamoto is the most popular person in Japan who creat the first Bitcoin in Japan. He is the computer programmer who invented the digital currency.