Steve Ballmer has, on his own and with Bill Gates made several critical blunders in shepparding Microsoft into 21st century.
While the company has grown, particularly in profitability under his tenure, that advantage should not be attributed to Ballmer but instead to the very shrewd and intuitive contract agreements Gates made with hardware manufacturers (OEMs) that effectively tied their financial obligation to Microsoft for every “computer manufactured” irregardless of quantity sold. This resulted in, for example, a large corporation purchasing 20,000 computer units “without” an Operating System (OS) installed, but for which the OEM still had to pay Microsoft for 20,000 copies of Windows (multiplied by) times Windows OEM price.
The principle reasons for Microsoft decline under Ballmer in minds of most technology and business related experts, stems from (a) Ballmer and Gates discounting early on the importance of the Internet and World Wide Web (WWW) ,which was quickly emerging as critical and defacto technology in early 2000s for all electronic communications, and for which Microsoft had little or no expertise, or worthwhile experience on global level.
The second (b), and related (to first) reason for the difficulties now facing Microsoft was that the company was never a truly innovative tchnology entity, which gleaned it's software products and services for other creators and developers, sometimes by litigation that other entity could not challenge financially and/or by secunding technology through cooperative projects that Microsot controlled.
Unfortunately for Microsoft, even with a smart leader like Satya Nadela , it is already too late for Microsoft to be a leader or dominate in areas such as Mobile – smartphones, tablets , social networking services, mass geographically distributed data centers for Mobile services, mostly run on Lunux, advanced Virtualization and Cloud Computing Services with "must-have" “Containerization” technology.
Steve Ballmer was basically an ineffective, loud anf bullying type leader who has no place in new technology age.