They are colossal money-wasters. There's not much in the Air Force budget that gives less bang for the buck than balloons with radars on them.
The Air Force is facing huge budget cuts across the board even before sequestration. Shutting down this useless boondoggle being run as a charity case for Customs and Border Protection is going to supposedly cost "hundreds of jobs" but it will save many millions of dollars, and it won't weaken US air defenses. If NORAD thought the balloons worked for defense against military adversaries, they'd undoubtedly make them a high priority and keep them.
My only problem with Obama and his handling of the Pentagon is that he's not cutting spending enough. We need to close hundreds of overseas bases and shut down all kinds of dubious "defense" systems which are just welfare for contractors as well as zeroing out foreign aid.
Take back the GOP and Restore America Now.