I think you underestimate the utility. Think of parents or family members that attend football games. They're often stuck watching the game "through the viewfinder" if they want to film it ... this frees them up to look with their eyes. You also underestimate extreme sports where you want to film a trick over a given obstacle. This would be fantastic for skateboarders. Boxers who want to film themselves during a workout, or a fight to review their form could use this for sure.

etc. etc. ... just because you don't anecdotally see the demand doesn't mean it's not there ;)