The most remarkable aspect of bitcoin is that if Satoshi is a single person, it's the first time in history someone has become a billionaire by themselves.
It's not quite that clear cut, but it's not too far off.
The only problem is that Satoshi's coins are watched like a hawk. Satoshi can't liquidate any of them, or even really move them without causing an immediate reaction in the community. Exchanges might halt trading, whilst it would immediately give away his or her identity. If the price of bitcoin doesn't crash following a coin movement, Satoshi's life is most certainly at risk. If it does, then the coins are worth nothing.
Satoshi is almost certainly dead. No living person could resist the temptation to talk about their creation of a 100 billion dollar phenomenon. Two plausible candidates who died at about the right time are Hal Finney and Dave Kleiman.
Edit: I misread the initial post, but still think what I wrote is reasonably relevant. Had I been Satoshi (and I'm not), I would have no trouble not talking about it.
I think this is unlikely. I think it is much more likely that he deleted his keys -- on purpose. Despite the common "Bitcoin was created as a scam" sentiment, I see very little evidence of this. Satoshi appears to have just been a very idealistic person who thought that he was doing something useful. From the beginning he said that he shouldn't hang on to those initial coins because it would undermine the validity of the currency. Out of curiosity I've read through a fair amount of the original dev forum archives (I forget where they are, but I'm sure they are not hard to find -- last time I looked I found them right away). As far as I can tell, it is what it appears to be. Which is not, of course, to say that there aren't plenty of scammers in the Bitcoin world. It just seems that Satoshi wasn't one of them.
Name an artist who has stayed anonymous under focused public scrutiny as effectively as Satoshi. The only one I can think of that comes close to this level of exposure is Banksy, and his identity is right there on his Wikipedia page for anyone who really cares to know.
Besides, Banksy does plenty of communication despite his supposed anonymity. It's not the anonymity; the total lack of communication from Satoshi is what makes me suspect he is dead. Even famously reclusive artists such as Bill Watterson don't cut off all communication with everyone.
The anonymity of Jane Austen was not remotely similar to Satoshi. Plenty of people knew her identity. According to Wikipedia she was contacted directly by the king's librarian. Also that was in the 1700s! In Satoshi's case, it's possible that no person on Earth has ever known his true identity other than himself.
But that's all beside the point. You misunderstand my claim. I'm not claiming that it's unlikely for Satoshi to want to remain anonymous. What's unlikely is for a successful person to not talk to anyone, not a single other person in the world (as far as we know), about their success. Even people who value their privacy and anonymity very highly typically still want to communicate with other people somehow. Satoshi clearly had good communication skills, and knew how to communicate while remaining anonymous, so if you want to argue that he was some kind of loner recluse who rejected communication with other humans you'll have a tough time convincing me of that.
There was nothing stopping Satoshi re-joining and buying back 100,000 cheap coins once there was enough transactions to hide the fact that it wasn't him.
Much easier to steal a private key than liquidate a billion dollars from many banks and other illiquid sources. Especially when most of those transactions can be reversed, or otherwise raise immediate red flags.
But if you have his private key you still need to convert the Bitcoins. This isn't easy to do anonymously, as can be seen with Alexander Vinnik's arrest. If someone actually robbed Satoshi and let him live, he'd probably alert the world and the wallet would be watched like a hawk. And even if he's dead or unaware of the theft, a lot of people will notice of Satoshi's Bitcoins start being transferred.
Their billions are liquid and can be used to buy protection (secluded homes, private transportation), Satoshi's aren't (in so far as he hasn't liquidated them).
I don't follow. By themselves means? If he wants a billion dollars he still needs someone to trade it from somebody willing to trade with Bitcoin. How is that different from Bill Gates?
Nobody in this world does anything 'by themselves' by any reasonable definition. Satoshi built incredible things on the shoulders of other incredible things, like roads, the internet, computers, etc.
It's not quite that clear cut, but it's not too far off.