Will Wilkinson summarizes some discussion of the relevance of business experience to being President. One of the tropes that he mentions (without endorsing it) is that "business people don't realize that when you come to Washington you just can't boss people around. It's not as easy as it is when you're CEO."
Actually, that is completely wrong. In business it is actually really hard to get people to do what you want. In fact, understanding that fact is exactly what sets CEOs apart from policy wonks. Policy wonks think that you write a law and that solves a problem. They think that you promulgate regulations and people do not figure out how to game those regulations.
Someone with business experience would never announce a mortgage loan modification program and expect it to be implemented in a matter of weeks (remember, a mortgage is a legal document that is somewhat antiquated with procedures that differ by state and local jurisdiction; remember that, prior to 2008, mortgage servicers had very few staff with any experience at all in loan modification; remember that when you introduce entirely new parameters into a highly computerized business process, somebody has to determine which systems are impacted, gather requirements, redesign databases, develop logic to protect against data input errors, develop a test plan,...). Someone with business experience would not enact a program that fines companies for failing to use a fuel that does not yet exist. Someone with business experience, I dare say, would understand that chaotic organization has consequences.
I am not saying that business experience is the be-all and end-all. I am not saying that it should be required of a Presidential candidate. But when Congress and the Administration are permeated with people who lack business experience, this has consequences, and the consequences are not good.