When was the last time you saw a movie in 3D? The new tech is nothing like what was inflicted on moviegoers in the 80's. I suffer from migraines, and not one digital 3D film I've seen this decade has caused me any problems. The stuff I saw in the 80's did though.
I do agree that processing something shot flat into 3D is a something of a ripoff. I wish the studios would dust off some of the 50's 3D films, and show people how it was done old school.