I wonder what an instructor at an event with the rule about traction control would say if I showed up in my GTI. Craptastic "passive" seat belts (they work, but man they seem to confuse the crap out of everyone that goes to get in), no ABS, no TCS, no assists at all, noisy as hell, way faster than it has any right to be, etc.
I can understand where the concern with TCS comes from, I was instructing a guy at autocross that had TCS on and we agreed we'd turn it off by the end of the day... He was driving fairly smoothly and never had a problem controlling the car so I was concerned. He learned how much power his car actually has when he turned off the TCS, but he always controlled the oversteer well and I never felt in danger. That kind of experience would be very different on a race track with things to hit. There are plenty of people that have literally zero concept of throttle control, I see plenty of people driving around that just mat the gas or full lift and brake everywhere. ON-OFF switch problems.
The guy I was instructing was nothing like that, but just didn't know where the limits were. How do you learn where the limits are if the car is always handling that for you? The stupid TCS light is a bad indicator as I've had mine come on leaving my driveway at home, lol