My point is a very simple one: the DoD is as large as it is because the US has a cultural aversion to accepting welfare. We can't make it obvious that we want to build a large, well-educated, and financially stable middle class by dumping money onto it, so we build it up by dumping money into the DoD instead and ensuring that just about every (genuinely innovative!) facet of American industry gets a piece of the pie.
When the DoD is built into the lifeblood of your middle class like this, it is culturally impossible to audit it, because auditing it would reveal the truth so many Americans find embarrassing or politically repugnant: that their livelihoods come from government-driven funding intended to give them decent lives, not the invisible hand of the market.