As a VR dev I'm seeing a lot of users spending significant time in my game. It's, AFAIK, the longest dedicated Vive story-based game, so that might explain some of the longer play times.

(Left-Hand Path - http://store.steampowered.com/app/488760 . Horror RPG with a heavy Dark Souls influence).

But still - it's clear that there are a lot of people playing VR games consistently.

(I also play VR games quite a bit, but I'm just a single data point.)