If you've been paying attention for the last three years, almost everyone thought the US government would crack down on bitcoin with a vengence, satoshi very well may have been genuinely fearful of the ramifications of his software.
It is also possible that satoshi is a group of people and not a person.
Lastly, the idiosyncratic nature of someone who spends their time on crypto mailing lists and making crypto currency is likely to take privacy seriously for its own sake.
A better question might be, why would satoshi want to be found out?
If he is not motivated by anything like ego or credit then - as Charleton Heston would have said in a lame 50s Bible movie - 'He really is the son of God.'
Me neither. As it appears he have not premined any significant amount of bitcoins, so it's not like he is going to cash out. So the version, besides that he wants to be "hidden super character" may be that he was not allowed by some organization to reveal who made this breakthrough. It's not even clear if it was a single person. But even if it was by some organization, why hide? Maybe they didn't want bitcoins forever be associated with NSA for example, which would repulse people and led into believing that the organization controls the currency. But it still doesn't make much sense.
Since Satoshi seems to be heavily influenced by cypherpunk community, maybe it really is one person who just wanted the bitcoin really work and made everything that's the best for the currency? If so, one day, when bitcoin or it's derivative will be a thing on which the world economy depends, he will be the man of the year. Maybe he will even disclose his identity, since that will not have an effect on bitcoin itself any more.
Founder's syndrome (http://en.wikipedia.org/wiki/Founder%27s_syndrome) is a common problem that Satoshi nicely sidestepped for Bitcoin. Bitcoin is a zero-trust system, it should be judged on its merits, not extrapolations of its creators motivations.
The 1.5M claim is bullshit, however. People come up with these gigantic numbers by claiming that all coins unspent mined in the first year (or all coins mined in the first year at all!) were Satoshi. This is known to be untrue because there are many other people who mined in the first year and have coins unspent (or lost!) from then.
Yes, but the 1M number there is simply counting up all the unspent blocks in the first year. Though the author presented an argument for further distinguishing blocks into "maybe satoshi" "not satoshi" sets, that wasn't actually done for the count.
What if Satoshi is actually a group of NSA agents who created a new crypto-currency as a honey-trap to attract bad guys so that they could either stop them or use them as slave agents. What if?
