In my real world race car, I never get brake fade. Never. This is because I choose a pad that operates best within the temperature range that is optimal for my car. Brake fade happens when you are using the wrong brakes for the type of racing that you are doing.
I guess I would be in support of a model for street cars that would emulate brake fade on stock pads, but then it would be one of the first items that I would upgrade. So why should PD program something that every online racer would just upgrade anyway? Even for endurance racing, teams pick pads for the application. With the quality of racing brakes today, race drivers around the world are not fighting brake fade unless there is a problem with their equipment. People are asking for something that is useless, in my opinion.