Is it possible that Satoshi Nak. is dead and we are just spending pointless time trying to figure out who he is?
Yes. It's possible.
Or do we know for a fact that he is alive and just wants to stay anonymous?
There's no way to know unless he comes forward to say he's alive.
What do you think satoshi's reasons are for wanting to remain anonymous?
I don't know, I don't care. It really doesn't interest me. I'm not sure why anyone else cares.