People who pay $30-45K for a "premium" sportscar expect it to be "smooth" and "silky" feeling. They want as little vibration, sound and road feel as possible comming into the cabin. The pulley reduces the vibration from the engine to this end. IMHO, this is along the same lines as why the Z32 didn't come with a lighter flywheel. The 16 yo chic and the 65 yo gramma and grandpa don't want the car to stall if they let the clutch out a bit too quickly and aren't paying attention. But the point is, they never pay attention because they aren't "drivers", they are merely people using the car as transportation and/or to pose.
I'll take a bit more vibration and a faster responding drivetrain because I am a driver, thank you. Same reason I wouldn't even OWN an slushbox car, even if it was given to me.