Satoshi Nakamoto created bitcoin to be anonymity therefore he has to be anonymity as well because if he shows himself then the US government will arrest him and ask him to destroy bitcoin. And they will be different accusations on him and the one they will use to against him is the money laundering.
Good luck to them then if they could actually prove this. But you are right and I think many bitcoin enthusiasts have not stopped to think about that for a moment, they probably think satoshi is untouchable or immoral.
But in reality he can be in great danger not only from the government but also from people who have ill intentions in general.