Those 'basic precautions' will not be cheap and would probably require the liquidation of some of their bitcoins since they probably aren't anything like as wealthy in non-bitcoin terms. Liquidating their bitcoins would damage their psuedonymity, which is something that they are clearly not keen to do.
The other thing is that most of those centa-millionaires are not keeping their holdings entirely in cash that can be moved quickly in large quantities psuedonymously requiring only a small piece of information likely to be held by Satoshi.
Certainly, securing multi-millionaires is not an insoluable problem (although it fails sometimes), but I think that Satoshi is likely to be in a situation that make the consequences of being unmasked particularly dangerous and the difficulty of measures to keep safe particularly onerous.
The other thing is that most of those centa-millionaires are not keeping their holdings entirely in cash that can be moved quickly in large quantities psuedonymously requiring only a small piece of information likely to be held by Satoshi.
Certainly, securing multi-millionaires is not an insoluable problem (although it fails sometimes), but I think that Satoshi is likely to be in a situation that make the consequences of being unmasked particularly dangerous and the difficulty of measures to keep safe particularly onerous.