To be cynical ... the average American wants a quick fix that doesn't impact on their standard of living, doesn't offend their sense of entitlement and doesn't conflict with their (often unrealistic) beliefs. They are ignorant of science, overly reliant on their religious beliefs and paranoid about socialism (believing it = communism) and anything that might threaten their "right" to do as they want, when they want.
Obama and his administration inherited a mess from previous governments (mainly Bush, but it goes back further than that) just in time to face a situation the US has never been in before ... massive simultaneous economic, environmental, social, and security issues. There is no consensus on how to address the issues. In fact there is widespread denial that they even exist!
Sure, Obama is inexperienced, and probably was naive to think he could walk in and make the changes he promised. But the "system" ... government designed to provide "checks and balances", powerful lobbying by interest groups with a short term agenda, and media campaigns based on lies and half truths ... feeding an ignorant, self-centered, gullible and paranoid public makes change difficult if not impossible. The issues are divisive, the solutions expensive and painful. And the public expects everything to be solved without impact on their standard of living or lifestyle (despite that being exactly why the problems exist!) AND done instantly.
The sad thing is that Obama is one of the few who appear to have some grasp of the problems and reasonable ideas how to approach solving them. But in the US system he can't do it alone (he's President not dictator) and Congress is more part of the problem than the solution. The problem isn't Obama ... it's the American people and the representatives they elected. Until the latter change no-one can solve the problems facing the US.