What's the relation between Git and Markdown on the one hand and Windows on the other? SSH, yes, but the others? And there's nothing about Unix that limits its use to extraordinary people — I use it, as well as Git, Markdown, ssh, and even Emacs.
Have an Unix/Linux background makes it easier to get started because you already know what they are talking about.
My personal opinion? Windows sucks (just to be clear, that is me).