alt Hacker NewsAgreed, but what "prevents" it is that making a good keyboard-driven UI takes a lot of taste, extra effort to build it, and it must be revisited any time the UI changes. It's duplicated work.
Ideally all GUIs/TUIs are usable with keyboard and mouse independently.
A good example of this is when you have a fancy keyboard-driven workflow yet you can't even do the most trivial task without placing two hands on your keyboard. Sometimes I just want to reach over and do it with one hand on the trackpad.
> extra effort to build it
Also extra effort to use it. This is why we have the “how do I exit vim?” meme.
A good user interface needs escape hatches so users can keep their head above water while they learn to swim.
Most of what people want when they say keyboard-driven is closer to a cockpit (requires expert knowledge) than a general purpose UI.