Its hard question for answering why Satoshi Nakamoto remains secretly. a hard question which few people in the whole world may know the Answers,
But What if the scenario is Bitcoin designed to control people economically where few people know how to control it and the system lets people benefit from it with false indications on price (Demand and supply), It will be Easily to control people when all people in the world will be involved in Bitcoin
What are your Arguments?
If you are too afraid that Bitcoin "will control you" just don't use it.

You are not obligated by the law to use it.
You are legally obligated to use fiat money,which means that the banking system controls you,by having control over the value of "your" fiat money(which aren't exactly yours).
I think that Satoshi got disappointed by all the emerging altcoins and crypto exchange platforms.All this stuff made the crypto economy look like "casino capitalism". That's why he left.