back in the late 90's and have been using Linux ever since. I don't use Windows at all.
The real reasons people continue to use Windows are:
1. Laziness
2. Lack Of Courage
3. Proprietary lock in
4. Unwillingness to learn beyond their current computer knowledge level
5. Lazy smug Windows centric developers who could port their applications to Linux but are
a. Too comfortable in their inflated income Microsoft based lifestyle
b. Too lazy to learn other programming languages and methods to port their software to something besides Windows. These days there are lots of cross platform software applications that run in Linux and Windows. If some Windows only software doesn't have a Linux version its the fault of the developers for that software...NOT Linux.
I've been a Linux user since around 1997 or so. Its solid, does everything I need a computer to do and doesn't lock me in to spyware laden crap from a monopolistic company only in it for the money.
Over the years I've helped move numerous users to Linux. Almost all stayed with it. Many were basic computer users who were looking for a more stable environment without the constant headaches that come with Windows based operating systems.
Simply put once Windows users get fed up with all the bugs, spyware, virus/malware issues, forced upgrades, and other crap that comes with Microsoft's products they get to the point where they can finally overcome all the issues I listed above and make the move.
Does it work out for everyone. No, but those who make the move successfully suddenly realize that they no longer are at the mercy of their malfunctioning Windows based system. Their computer become what computers were originally intended to be. A tool. One that does what its told and doesn't demand your constant babysitting and attention.