Microsoft's behavior definitely does not preclude the possibility of its competitors simply failing or doing stupid things. This was certainly the case in the browser wars.
It's a shame OS/2 never succeeded better. I ran it for a while. I don't recall why I went back to Windows, but I do remember after a few months of suffering under Windows 95, I switched to NT and never went back. I've run Linux on and off over the years (I always have at least one Linux server, but my main machine has gone between Linux and Windows). The main reason I stick with Windows today is for games and a few other pieces of Windows software I really like using. It certainly isn't for anything Windows does that Linux can't do for me.
My wife, on the other hand, hated Windows 8 so much, she asked me to install Linux for her and she's been happy since. She's not a technical person, but she hated Windows 8 even more than me.