Because under normal circumstances this would be the appropriate response but we don't currently have normal circumstances.
Republicans have been determined from day one that the way to make Obama a one term President was to make America fail so they have obstructed all efforts by Obama to improve the economy. In 2010 the electorate determined that putting the Republicans back in charge in the House would get things done. Of course the opposite happened. Most Americans still don't understand what is happening and are again poised to cast am irrational vote. Should Romney be elected this country would be back in a steep recession within about 15 months and the reason is simple. Trickle down does not work. Period. Why that message cannot be driven home continues just boggles the mind.