Like it or not, some people just don't like to group and that's why I think you see barren VR zones. The average gamer (non-min/maxer) finds the content too difficult and therefore they simply move on to other things. (For the record I like to group for group content).
I'd suggest letting players recruit a solo companion (like in Skyrim - Lydia anyone?) for the VR areas only. Perhaps include companion choices from NPCs already encountered in the main story (Razum-dar for example). The game already allows for certain quest companions so I think the idea is able to be implemented with some tweaking. Gearing our comps would increase the value of crafting and possibly add another money sink to the game.
I'm just hit VR 5 & from what I understand things are about to get more difficult. I will probably head to Craglorn since the VR zones are barren.
Anyway, just a thought.