The point is if the "gui" can be keyboard operated, then it can be displayed as text, by the shell, with no need to augment/modify the terminal emulator to do it. In fact, even if it is only mouse operated, you can do that - most terminal emulators support mouse interaction. The only thing you achieve by adding this to terminal emulator is guarantee that it will be unavailable to you whenever you need to log into any of the systems you work on from someone elses machine.