I kind of agree. I have the same issue, although I'm not prone to motion sickness in life. My senses get ready for g-forces which are not there so my whole nerve system goes brrrrrrr. Then I need to put in mental effort to stop expecting motion and just concentrate on the visuals which ruins the experience. An hour in Digital Combat Simulator with VR is my maximum, and I usually need a recovery period for my internal gyroscopes to get in line.
I get sick in FPS type games in VR but have no problem with driving/flight sims. Weird how the brain works.
This is highly dependent on the user, though it is a common problem. I've personally never had any motion sickness in VR, whether playing flight sims (including helicopters) or driving sims.