Tim Geithner hasnt just been a bad Treasury , but he was a bad New York Fed President. He was right there in September 2008 when Hank Paulson decided not to rescue Lehman Brothers and tank the world economy. Geithner could have overriden Paulson and agreed to guarantee Lehman's trading obligations until a deal could be done, but he decided to just stand there and do nothing. This alone should have disqualified Geithner frmo the position of Treasury Secretary.
But that's only part of the problem with Geithner.
In summer 2009, with the economy still in horrible shape, Geithner convinced Obama not to push for anymore stimulus spending. More stimulus spending was clearly needed to get people back to work, but for whatever reason, Geithner was against it.
Geithner is also the reason why Obama has been so easy on Wall Street. A populist campaign against Wall Street like FDR could have rallied more support for Obama and helped the Democratic party as a whole, but instead, Obama followed Geithner and led the Democratic party and economy to doom.
Every decision that Tim Geithner has been involved in has been wrong. From Lehman, to the stimulus spending, and support for Wall Street, they have all been wrong.
Maybe Obama isnt firing Geithner because he agrees with him.