Because automakers aren't in the business of supporting privateer drivers who have differing opinions on track prep and level of talent? Both parties share responsibility. The first is that the automaker should build the vehicle for the purpose intended and second the owner should be aware of their responsibility to prep the vehicle accordingly and not destroy the car. Even professional drivers have a responsibility to not break the vehicle in their quest to finish first.Why sell as car as sporty then ding the buyer for using the car in a sporty way.