The US Treasury handing out $600 billion to people for nothing in return is no different than handing $600 billion to defense spending for nothing in return.
Our current deficit reflects around 50 years of defense spending, plus interest. The US could pint on coin, deposit it with the Fed, and wipe away the debt. What would change? Seriously, what would change? And if there is a good answer to that question, then we shouldn't be spending what we spend on defense. If there is not a good answer to that question, then there is no answer to handing out money for reasons other than defense.