I wonder if this 40-70% demographic has actively tried to play it a couple times? My first experience with VR was incredibly disorienting, and yes, made me feel nauseated. But after playing for 2-3 hours across a handful of 15-20 minute sessions (passing it around a few friends for an evening) that just went away. Once the body uses it a bit and learns, even high-movement non-teleport movement games stop being an issue.
I wonder if I happen to be in that upper percent, or if the numbers in question are a matter of people who tried it once in their life and felt sick. Clearly the author has put real time into trying to move past it, but that doesn't say anything for the study he quotes the "40-70% of players are 15 minutes" numbers from.