This is a good essay by Bret Victor (not me) from last year about current UI’s being about “objects under glass”
jon, Greenman, I think it comes down to better signals and affordances to inform usage. 2D or 3D interfaces can be really challenging. 2d and 3D input methods can also be really challenging. I think we’re at the infancy of mass adoption of these technologies and as 3D designers, we’re well positioned to influence and shape the future paradigms of input and interactions.