Casual Linux users, perhaps? I can't imagine anybody who's ever watched a casual computer user use a computer saying anything like the above quote.
Most people have the mouse in their hand the entire time, and usually don't have their other hand anywhere near the keyboard. Typing involves not only clicking into a box and dropping the mouse, but actually leaning the entire body forward in order to reach the keyboard.
Even I, computer programmer by trade, spend the majority of my life in "first person shooter mode" rather than "typing mode" because most of a web dev's life is debugging things that happen in the browser (a mousish place), and pretty much anything you need to do along the code-analysis line can be done with a combination of pointing and left-handing.
If you make me drop my mouse every time I need to interact with an application on your OS, I don't think I'll use your OS.