OP, ask yourself: if you invented competition to the traditional banking and monetary system, would you like your identity to be known?
the entity using the satoshi pseudonym is one person. that is established.
Any conclusive investigations regarding if he was indeed a single entity or not?
This answer is really plausible. If I invented bitcoin, I prefer to hide. I am sure many secret services is looking for Mr. Satoshi now. The government is following bitcoin for more profit and also for the control of cryptocurrencies world. We nearly all know here cryptocurrencies is the future form of paper money. Don't you think the governments know this?