20%-80%? I wasn't aware the proportion was so high. Of the 12-or-so folks I've put in VR over the past few years for more than 1 hour, only one reported experiencing motion sickness, and that was after about 15 minutes. It's certainly a thing that exists. I'm more on the "iron stomach" end of the spectrum, but I hear that ginger candy can help, and as another commenter suggested, chewing gum. Some folks have reported that having a fan blowing air at them can help as well. Those sorts of measures might not be very attractive if a person hates VR anyway, but if they really enjoy it and want to work around the motion sickness, it might be worth it.

For what it's worth, I don't think this is unique to VR...I used to be a big FPS player back in the day (Quake 1-3 mostly), and I had a friend that got motion sick playing Quake 3, so he couldn't play in our matches. It's certainly the case that I've heard more reports of motion sickness in VR, though.