Gaming went mainstream because it went mainstream. Technogy improved, it became easy to setup and play (unlike a computer at the time), competition was high between Sony and MS which resulted in quick generational leaps. And finally, all the gamers grew up inviting more gamers to be gamers.
Once it became big money, gaming attracted attention propelling it further.
Like any technology, it's a combination of things that leads to high uptake.
My opinion is that VR will go mainstream when it becomes afford, useful and easy to use. IMO we are years away from good useful VR.
Maybe vr gaming is it? I hope so because I’d like to see the platform grow from there into other application areas.
Personally I’m curious if I can use it for something, maybe data visualization. Like a more powerful matplotlib. Maybe I’ll just try it if it’s affordable to try and possible to use it that way (custom code).