The Z32's driveshaft is relatively long. It's not at all about being able to make a 1-piece fit, it's about mass producing 1-piece driveshafts which are all perfectly balanced. If you have a center support bearing, the driveshaft doesn't need to be as delicately balanced and thus manufacturing costs are decreased. When a 1-piece is made, more testing must be done to ensure that it will not vibrate at speed.
I love elitists who aren't really elite in any way... they amuse me greatly.