First of all, businessmen make very poor political leaders - completely different skill set. The government is not a business. Study the Craig Benson disaster in NH for a recent example.
Second of all, why would Mitt being a businessman help turn America back to capitalism? Big business is aggressively anticapitalist, and works constantly with government to rig the game against small business and US workers.
If the job description was Administrator of the Executive Branch, Mitt would be perfect.
But it's much, much more than that.
The most bizarre thing about Craig Benson's flop was that it was mostly about alienating his own friends and supporters. He wasn't brought down by his enemies. He had this close circle of allies and wouldn't let anyone else into the circle even if they wanted to be allies, too. He was fiercely loyal to his inner circle and treated the people outside the circle who liked him like they were idiots. Craig Benson was on a fast track to running for president this year and totally blew it. He wasn't even a bad governor. He just was really bad at the people side of politics.