The reason Bill Gates gave him the reigns as CEO is that besides Gates he's the person most singly responsible for Microsoft success. Circa 1998 they were the most valuable company in the world with a market cap of $500+ billion. Early in Ballmer's CEO tenure, they returned one of the largest dividends in history. It was an economic event so large that the Federal Reserve cited it as affecting the macro economy.
The author ignores that people price in their view of the future of a company, and Ballmer's Microsoft isn't viewed as having a great future. Very possibly not even a good future.
In fact, if this parody of how Microsoft was being managed was correct, all these billion dollar new market effort flubs wouldn't be happening and the stock just might be doing better. At the very least the unprofitably invested money could have been returned to the stockholders.