There was wisdom in the destruction. 

At the time, there was a real possibility that if the Japanese attacked Hawaii again, they could defeat the US military there and occupy the Islands. 

And, if they did, they would likely do the same thing they had done before in other locations. Confiscate all the money, and use the cash to bankroll their military. 

Then somebody came up with a brilliant idea – let’s get rid of all the cash before they get here! 

They could gather it up, and send by ship back to the mainland – but no – what if the Japanese captured the ship? That was just too risky. 

But if they just burned it all – yes – that would work!