Ballmer was back in the company then. People outside MSFT underestimate the technical know how of SteveB - he ran release management for the first version of Windows. He understands software. He might be doing a terrible job the last decade but that is not due to him being some 'MBA' stereotype.

Also - BillG really trusts Steve. They've worked together for over 25 years.

This is a really good point. Ballmer may not be the greatest CEO ever, but he does understand Microsoft products and what engineering goes on behind them. His interview in which he made fun of IBM wanting metrics like KLOC and judging quality by that shows that he had some clue even back then (~12-13 years ago).