Gran Turismo would have been just another racing game, that's what.
Actually, that was a little glib... to heck with supper for a bit. Let me be more explicit. Without Kaz, Gran Turismo would be just another racing game.
What specifically? Probably Need For Speed, but a scouche more serious. Race car and supercar heavy, and not all that many cars. Maybe slanted to the European side, since they end up buying most of the games. Would it stand out? I'm dubious on that.
Like it or not, Kaz created something unique. I'm unaware of any other racing developer who wanted to make their game an encyclopedia of cars, because they flat out love cars. A guy who made it his goal to create a game that had you driving some of the most head scratching cars in the world because some car maker had the desire to make it and bring it to life. Who put license tests in the game to make us students of driving technique. As aggravating as that ended up being sometimes. A guy who made the music an integral part of the experience.
What other racer sticks out of the pack as something different? For many of us, it's just GT and Forza. And when MS decided to make a flagship racer, who did they copy?
Would Project CARS have street cars in it if not for GT? I doubt it.
Why do millions of us keep coming back every time? Made GT5 Prologue a platinum seller just from pre-orders? Because we can't find anything else like it. Or the man who's at the helm.
The guy at the top matters, and if he's unique, he really matters. Alien and Blade Runner wouldn't have been half the movies they were without Ridley Scott directing and making the actors sweat blood. Someone above mentioned Hideo Kojima, another archtypical studio head. And then there's Kaz.
I doubt I'd care much for Gran Turismo if not for Kaz.