Fortunately it is not as grim as you describe. People have different levels of resistance to motion sickness. Even with titles that offer significant disconnect between physical and virtual motion (e.g Climbey), an hour is something that for me is easily achivable and enjoyable (and even beyond that it's more a problem of getting physically tired of the activity, than of motion sickness). I believe I am not that unique in that regard and there is actually significant percentage of population who could also easily go beyond those "15 minutes of VR".