That's a problem with the specific GUI, not GUI as a concept. Good GUI frameworks should be built for predictability and keyboard-driven fast paths, and have this included by default so you don't have to make these decisions for each app.

In fact, all successful applications for professionals/power users are built with fast paths in mind. Even Microsoft's ribbon which gets a lot of hate for some reason is an example of that, it's keyboard-driven, customizable, and discoverable at the same time.