My first reaction to your question was - “how is that any of your concern?  Satoshi obviously wants anonymity and that’s all that matters.”  You talk of him not having done anything illegal, so instead I invite you to read the transcript of Julian Assange’s testimony to PACE last week.  In it you will find a first hand account of how the US and UK governments trampled over laws designed to protect journalists and whistleblowers (including the United States Constitution, no less) to pursue a vendetta against a journalist who showed them for the murderers and thieves they are.

The state does not like its power to be challenged.  Satoshi knew this and kept his identity secret for this reason. In fact you may recall him practically begging Assange in 2010 not to accept #bitcoin donations, given the heat it would bring down on the network which was at that point still in its infancy.

He chose wisely and we should respect that.