Occasionally, various quotes from people having an opinion if linux is about choice or not. Even pages like http://www.islinuxaboutchoice.com/ has shown up.
My short answer is “YES”. Linux is about choice. And you get all your choices directly from your f/loss definition of choice (FSF’s 4 freedoms / OSI’s opensource definition / Debian Free Software Guidelines)
It doesn’t mean that you get all the gui configuration bits that you want. It doesn’t mean that you without any problems can switch out any component. But it does mean that you can get it exactly your way. But it might require you to edit some source code and compile some stuff.