Bingo. Before there was beautiful Graphical User Interfaces there was completely text-based operating systems. Most, if not all of the shortcuts used back in the day still remain. It is much, much quicker to use shortcuts and run commands then the time it takes to use a mouse to point and click on something. For e.g. you could click the address bar, typed your website, then click go. Or in the browser you can press Alt+D, type your website, then hit enter or shift enter (browser dependent), and your hand doesn’t even need to touch the mouse.

Not to mention, a lot of hacking is done on Linux-based operating systems. Which once again, don’t have much of a focus on a GUI.