I believe it was intended to limit braking performance. Smaller rims mean you have to fit smaller brake discs and the more confined space traps more heat. This increasing braking distances and so increases the window within which braking zone overtakes can be attempted. All the best, Andrew.
That's not the only thing. That's the point I'm making. Others brought up braking. But you get more sidewall deflection with the high profile tires, which affects the contact patch negatively. Or at least you used to. Tire tech has progressed amazingly since the 90's or aughts when I read that.
