I think Satoshi Nakamoto doesn't really want to be known for the reason of Bitcoin. He/she might be thinking that Bitcoin will be an open source and decentralized electronic cash, revealing himself/herself will only cause a ruckus of him/her being the one manipulating the price. Also I think the creation of bitcoin was only a hobby and past time for him.

Revealing his/her true identity will not bring any gain to him, thus will only bring problems about the people who want him to go down.

Thinking of the some government that doesn't want bitcoin, they will surely make things to bring him down, together with the price of bitcoin