Good idea for whom is what you should be asking. That money wasn't burned, it was sent to the bank accounts of major stockholders in Raytheon, Lockheed Martin, Halliburton etc... Lets be very clear, there are people who benefited and still benefit greatly from US Military spending.
As there are people who benefit from bank robbery. After all, the money is still around to be spent by the bank robbers.
But it's still theft from the system and is a transfer of purchasing power from those who produce to those who do not. Or in case of military contractors, from those who produce to those who destroy. Professionally.
Have you seen the footage of bombing of ISIS cash dump with US currency flying out? Guess the pallets of dollars going over there for reconstruction was the source.
It's a waste. Waste of spending, waste of effort, waste of resources. The human effort and material spent on that endeavor could have done a lot for this country.
Also morality aside, if we are empire, if we are going to police the world, we are doing so in a very unsustainable fashion.
This is just what I can't help but see. Maybe I'm wrong. Not really trying to argue but damn, this a big elephant of wasteful effort and resource allocation.