If I were Satoshi I'd keep my head down. I wouldn't want my life f-d up by outing myself.
Think about the kind of world view you need to have to decide to dedicate the necessary time to develop a system for transacting outside of approved channels. Dude's probably worried about polonium finding its way into his tea or whatever.
Assuming he is even an individual.
What would killing him achieve? The Bitcoin technology is out of his control.