There are a few things worth noting when talking about Balmer and MSFT's share price. Since 2004, MSFT has returned over $164 billion  to shareholders in a ~50/50 split of buybacks and dividends -- on today's balance sheet, that cash would be worth an incremental ~$20/share (assuming $0 reinvested). Meanwhile, revenue and free cash flow have grown at a respectable 12.4% compounded, and it wasn't until 2012 that Apple passed Microsoft in terms of gross profit.
I don't think anyone would argue that Ballmer's been the most innovative CEO of his era, but as a custodian of shareholder value, it's pretty hard to fault him. Could he have done better? In hindsight, we know the answer is yes, but the answer in hindsight is always yes. He managed to try and fail at big ideas without bankrupting -- or even significantly impairing -- his company. Not many CEOs can claim the same.
What happened to Microsoft? It built and sold unsexy products that people were willing to pay gobs of money for. I'm sure many businesses would love to fail so successfully.