A similar argument can be made that touch-typing isn't really necessary to get good use out of a computer. This doesn't negate the fact that someone who learns it (and by extension might take the time to learn keyboard combinations) has a good chance of out-performing someone else who hasn't learned one or both in terms of "raw speed to do a task" in text-editing environments.

In "visual logic" or "block" programming, there's obviously no comparison since the mouse is actually required...

But going back to the shower thought that hacker-types in movies don't appear to use the mouse often, this is appropriate because the tools such a person typically uses are much more suited for keyboard-only interaction, even in their programming environments.

And all of this can be done at least as quickly with a keyboard (in, e.g., Emacs, vi, etc.), it's only that modern programs have tried to make the mouse more useful for those who insist on using it...