Why? Not like it's accurate? When I put my foot down in my car, the front doesn't lift up in the air!

The extreme movement is to allow the rider to experience the same G-force that you would feel in a real race car.

So look at the screen, feel the gforce and it's as realistic as it gets.

Actually it does, just not as exaggerated as that.
However, having been in a more sophisticated version of this, they are very realistic. it is like the simulators you see at the pleasure beach or the car shows, but with out the shroud.

Well, yes.