What baffles me when I look at all these futuristic interfaces is that they do not take into consideration the most productive combination: keyboard+mouse+voice

What baffles me when I look at all these futuristic interfaces is that they do not take into consideration the most productive combination: keyboard+mouse+voice+3D depth. It would allow you do many things at once and as a result save time. Limiting users to gestures on flat surface looks nice and easy but isn't the fastest way to interact with stuff on the screen.