[gfodor]

as others have mentioned it's not a new idea. i think the reason you don't see it in Apple products at least is because it is a step backwards in terms of metaphor. the iPhone's core metaphor is direct manipulation. this requires that your brain visually connects the motion of your finger with the objects on screen. if you manipulated things via the back touchpad, this illusion would be broken and it would feel more like interfacing with a traditional computer and less like direct manipulation.

[arrel]

That sounds like the reason Apple refused to use a hardware button to trigger the camera shutter, but thankfully they caved on that one and I can take a photo without having to guess where I'm tapping the screen.

I'd rather see companies trying out ideas that might work instead of just sticking to their metaphorical guns.

[gfodor]

Well every design change is a trade off. Breaking metaphors, all other things being equal, is bad. The fact that the author here identifies an on screen cursor as a use case probably is enough to strike fear in any apple designer that this would lead to a regression in ux.