Until Apple makes a device that’s as capable as the Vision but as unobtrusive as a pair of glasses, it’s going to remain a niche item. The Apple Watch, as you mentioned, has the benefit of being the same general form factor as a watch. iPads are just fancy notebooks.

As much as he wishes it was true, Tim Cook is no Steve Jobs or Jony Ive.

(For reference, both devices you mentioned, as well as all of Apple’s successful devices since the first iPod, were products of their marketing genius.)