What if he is working on something new? Something that would outshine Bitcoin??
I think he is not working on anything new, since he is allready rich, first few thousands of BTC mined are his, i'm sure. This can be checked somehow i guess, who was the first miner and how much did he mine so far ?
He has little ways of being able to cash out of his bitcoin holdings. So while he may have a lot of assets (bitcoin) he has no way of exchanging them for goods/services that he needs.