I'm glad somebody finally brought it up. As a device for TV and film the transparent interfaces work because they allow the camera to see the face of the actor through the visuals as it pans around the bridge or wherever.

As a practical interface though the UX is all over the place. Transparent interfaces suspended from a hologrammatical hardware have no privacy and require very dark surroundings to become remotely legible.

An AR interface only the user can see (like the Focus interface from Horizon Zero Dawn) works because it has useful transparency but also privacy.