Originally Posted by rhouck
Because it's safer (for the many reasons stated above). Kind of like wearing a helmet, which afaik you don't need to do at certain tracks in Europe either. You are correct that you get debris, aero is worse, and it is noisy
But it's certainly not "nonsense".
OK, "nonsense" is maybe a too strong expression in this case, but still I would hate it if I have to do it. On track days here you usually have to wear a helmet, only during tourist rides at the Nürburgring you are allowed to drive without a helmet.