The answer to your accusations lie in the difference between game and reality. If you're in a real car, facing a real course, with real death as a possiblity, you're going to alter your approach somewhat. You're not going to take as huge a risk, because it could cost you dearly.
However, if you're playing a game with no consequences, who cares if you screw up and t-bone the wall at 150+mph? You'll just do it right the next lap. Your approach is reckless and pushes toward the limits of the car and the track.
Another difference between the game and reality is that you don't feel the g-forces, the heat, the shimmer effect of a mirage screwing up your sightlines, the upsetting vibrations of the road, etc. that would normally throw you WAY off in real-life circuit racing.
If Niki Lauda had been racing in GT4, the kink immediately before Bergwerk would not be called "Lauda Links" because his crash would have been immaterial. Just a bad lap. Fact is, he was racing in real life and it cost him. Because others didn't want to be set on fire, also, they decide to play it a little safer and drive somewhat slower than what is "theoretically" possible.
There have been numerous reports on this matter, not the least credible of which was from the mouth of Jeremy Clarkson himself. It's well established.
