I must call BS on this comment. I KNOW for a fact that it is NOT so!
As a rider of both Sport bikes for many years and cruisers (V2K & R3R) for the past 12 years, I'm here to report that I can operate twisties WAY faster on a sport bike than on my R3R. I too have enjoyed embarrassing some sport riders on my R3R and even a few aboard my V2K; however, rider skill being equal or better than I = NO WAY!
I further doubt you are near as good in the twisties as you purport.