I disagree. Tech companies need tech leadership, and Ballmer didn't have the chops for that, or imagination either. He got some deals done, I'm sure.
How so? Missed mobile after working on it for a decade+ previously. Despite developers⁴ they didn't implement a decent terminal until a few years ago, thirty years late. Enough said.
It's probably better for the industry Ballmer was mediocre or worse. I'm often forced to do business with Microsoft already. His horrible deal to buy Yahoo would have improved the playing field further.