I feel that big money follows big money. Bill Gates is big money. The guy rules the computer operating roost...and then some.
Back I the 80s the USAF and the rest of DOD used software called Enable. It was a suite of software that included word processing, spreadsheet, and a relational database. The USAF later went to WordPerfect, Lotus 1-2-3, and dBase. In the field of presentation software, we use Harvard Graphic. A few years into the 1990s, Microsoft pushed its own integrated software suite. This was called Microsoft Office. DOD embraced the Microsoft platform and the rest is history.
Now Bill Gates has other ideas...Common Core. Microsoft wants to go into the teaching business to make a few bucks off our kids...and we'll pay for it!