Um? Because they do. I road race 3 different classes of vehicle. 2 of them stock classes. Where tires and safety equipment are the only allowed modifications. Even a “proporly tuned and engined” A body would get schooled and played with on track with any number of cars in the class. They just didn’t handle well at all. If you dont believe that, you’ve never driven a car that does handle well and actually used it to it’s potential. Yes absolutely an A body can be built to be a wicked corner carver, many have. I’m currently building one. But this conversation is about street cars, and the way these cars were built back then are no match for cars of today. A stock Honda Civic will run circles around your stock a body on any road that isn’t straight wether you believe it or not.