So, AFTER you've convinced the American tax payer to directly fund this kind of research, or you create an X-Prize crowded funded site, I think we should be thankful that the military is willing to "invest in the future" rather than just build bullets and bombs, which have no positive side effects.
Having a military is a necessary evil in the world in which we live. Find ways to turn some of it into a positive force.
eg. http://www.npr.org/2012/02/17/147047543/desert-military-base...
Consider that the US economy is $15 trillion. The US handbag market is bigger than DARPA's budget.
http://www.prweb.com/releases/handbags/leather_handbags/prwe...
How can we get more people to invest in science and engineering research? Hopefully, KickStarter and Petridish will eventualy lead to a boom in consumer funded science research.
If you want non-military research, give it to other agencies instead: NSF, ...
DARPA is a amazingly great idea, and a lot of their stuff makes their way to civilian applications. More DARPA, less 90,000 ton hardware.