I don't think that's why. TVs without 3D are just cheaper, the early 3D tech just wasn't very good and took awhile to mature thus souring the market, 3D content was more expensive (or an extra expense, eg. buy the 3D and non-3D versions of a movie) and so people just went for the cheaper options overall. I've had an active 3D TV for 10+ years, and the 3D has not itself been a problem when I've watched with others.
The only time it's a problem is if someone currently experience a migraine is trying to watch, then they can get serious vertigo, but that's an issue caused by the migraine itself (visual auras and vertigo generally).