The true explanation is just two words and very simple: It isn't.
I remember one scant generation ago when politicians at least made reference to the cost of shit like this. We've gone from days of people having at least a passing knowledge to economics to "WELL, WE HAVE PLENTY OF MONEY FOR WAR, SO WE HAVE PLENTY OF MONEY FOR THIS!"
In other words, DUmmies could not care less about the deficit, nor the fact that M1 is growing geometrically at this point. I am now buying things that are scarce, like precious metals. Scarcer still is the intellect of a liberal, but I wouldn't pay a plugged nickel for a bushel of that.