This is a fantastic observation! Having done research into UI/interaction design, I can confirm that all research in this area prioritizes things that (a) can

This is a fantastic observation! Having done research into UI/interaction design, I can confirm that all research in this area prioritizes things that (a) can be measured quickly and (b) with a high degree of confidence. Good luck running a controlled experiment where multiple folks use an interface for an entire week and then become power-users of the system!