So the money they earned doing it was no good to the economy?
Strange.
What good to the economy are scores of thousands dead and even more maimed?
None. But its a good thing most Americans had a big fat pay-check for a job well done from Uncle Sam to get the economy going. Imagine a few hundred thousand GI's back from the war, with money in the bank, ready to buy houses and cars, get married, have kids, go to college, start businesses - you'd think it might lead to the 1950's or something.
But no - its all a lie. The key to reviving the economy is to reduce spending. That way, there will be less demand for goods and services, and companies will have to lay off more workers. Which will lead to recovery, of course.