Just in that paragraph alone it's made obvious that he's not equating legislative and foreign policy accomplishments to performance as a whole considering he's saying that the economy is still in trouble and they have work to do. Presidents are judged on a host of issues beyond just legislative and foreign policy accomplishments like leadership, overseeing the economy, crisis management, scandals (or lack thereof), etc. This idea is bolstered by the fact that LBJ, who is known for his litany of legislative accomplishments, was included in the 3 exceptions as opposed to Washington, Teddy Roosevelt, or others.
Given that the first 2 years of Obama's term featured healthcare reform which had been attempted and failed by a number of presidents, the end of Don't Ask Don't Tell, the financial reform bill, the killing of Osama Bin Laden, the downfall of dictators in the Middle East, the winding down of the wars in Afghanistan and Iraq, and many other smaller accomplishments, his claim is not that outlandish. How many other presidents have a comparable record purely in those areas? Is there really anyone who believes that Obama thinks he's a better president than George Washington? Only those who suffer from the kind of anti-Obama derangement that members of the House GOP do. It's just another example of people not really paying attention to what someone is saying and going for a cheap headline.