One of the reasons it's done this way is to teach you to ignore inter ear cues and trust your instruments. Your inter ear senses acceleration, not absolute motion. Couple that with the centrifugal force during a turn changing your perception of which way "down" is, and your body responses become one of the main reasons you get into trouble.
It's similar to banked turns on car racetracks. When you're in a banked turn, "Down" for you is no longer towards the center of the earth, it's at an angle, perpendicular to the speedway. You also loose the sensation of turning once you're in that banked turn long enough (specifically once the fluid in your ear settles down and stops moving). If you were driving with a blindfold, you wouldn't be able to feel how steep your turn was.
[1]: http://sportys.com/pilotshop/category/864 "View Limiting Devices"
I guess what I was getting at was not so much that you could survive with your inner ear, but that you get a lot of feedback from a vehicle that you don't in a simulator. That's not relevant to this study if they didn't use a simulator, though...
People driving cars in simulators also do worse than in the real thing - a simulated car doesn't have all the ways a car tells you that you're driving close to the envelope.