I recently picked up a first person game for the first time in quite a few years, and I was surprised to discover I got a little motion sickness after a few hours. It was fairly mild, but it's not an experience I'm keen to repeat for the sake of entertainment.
It's a huge, unsolved issue that affects a not insignificant portion of people.
I got some truly awful nausea that lasted nearly 48 hours! I felt like I broke my brain. But I was running a DK2 on a wayyy underpowered rMBP on early firmware.
I quickly learned: (1) if a game has judder or is otherwise not running smoothly, do not play it; and (2) do not move unnaturally (i.e. no fast strafing or running like in a FPS).
When I followed those two rules, the nausea disappeared and when I felt presence it was mind blowing.
I don't doubt that some people may have unavoidable motion sickness, but I wonder how many reports are due to people like me running early dev kit software on underpowered hardware, and playing games with mechanics not meant for VR. There may be some subset that just can't play without some nausea, but the same is true for riding in cars or on boats.
You're right about FPS strafing and some other unnatural movement, that seems to make things worse for some people.
Additionally, I think the situation might improve if you really take the time to adjust the lenses and the headset to match your head and eyes. This makes the Oculus headset a "personal" device in that you can't really borrow or share one, though.
However, I got terrible nausea that lasted for the rest of the day and rendered me incapable of doing any work (fucked up my eyes so I couldn't focus on text) after just 30 minutes of play. I'll need a pretty good reason to try it again.
