I think his motivation behind Bitcoin is as clear as it can be, which is to provide an alternative to everything that's centralized and permission based in form of peer to peer transactions. Pretty valid motivation if you ask me.

It's also not a surprise that Bitcoin popped up during the credit crisis back in 2008/2009. I am even of believe that satoshi wasn't planning to go 'public' that soon, but used the crisis as stimulating factor, and it really was.

I honestly don't even want to know who satoshi is. I can only say that I'm thankful that we have a working tool that's meant to bring in more economical freedom for basically everyone, and we're still at the very beginning.