Because driver involvement is more fun than just going fast. Try riding a Jap 600 SuperSports anywhere close to the speed limits and then ride a Ducati 900SS (which is slower in just about every quantitative metric)
I rest my case.
But I cannot understand anyone who prefers the looks of a 9N3 to a 6R - and I own a 9N3 :P But then I also like the look of the MkVI Golf (and can't stand the look of any recent Subaru)
Apples, I was going to hit on you - asiastic chick who likes to drive - until you mentioned the fiance ;)