But back to MS: they absolutely are critical and relevant, because everyone's PC runs on their software.
Seriously, when you use hyperbole and straight-out lie, I stop listening. There are a lot of PCs that don't run on Windows. Millions run Mac OS, Various Linux distros, and Chrome Os is making a huge dent in the educational market. Windows and MS Office isn't as important and prevalent as they used to be. They are a hugely important company, but they are not as influential on the PC market as they used to be.