I use Microsoft because I know how to use it, and don't have the time or the inclination to learn to use anything else. Until all the games and software I want to buy becomes available on Linux without me having to do anything extra to make them work, then I will stick with Windows. Why? Because is designed to work on there.
I use Microsoft because as far as I am concerned, their products do what I want them to do. I've used Microsoft stuff for 10 years, and not had any major problems. If and when Microsoft fails me, or can't do what I want it to, then I might start looking elsewhere. Right now, this is not the case. My computer works how it want it to. I've not come across anything I've needed to do that I can't. I don't spend hours at my computer tinkering with it to make it do other stuff. I turn it on, browse the internet or type an essay and play a game, and turn it off. Since every game I have bought works with Windows, and since I've completed all required college work using Microsoft Office, I don't see the need to go messing around with things and break them trying to make it better.
I've tried FireFox, and I didn't like it.
I've tried a Mac, and I hated the damn machine.
Nothing any of you can say will change my mind, you're preaching to a brick wall here.