70 different versions of the MV-22 with a production run of 129? Concurrency or idiocy?

via AOL Breaking Defense.

If you’re a pilot or mechanic working on the Marine Corps’ prized V-22 Osprey, you probably spend a lot of time reinventing the wheel. That’s because the 129 MV-22Bs in service come in more than 70 different configurations, identical to the untrained eye but all subtly different — for example, in the cockpit layout, the electrical wiring, even the arrangement of bolts — which means they require subtly different flight checklists, maintenance procedures, and spare parts. If it’s not a logistical nightmare, it’s at least an acute headache. And more expensive than it needs to be.

Story here. 

129 MV-22's with 70 different configurations.

HOW THE FUCK DOES THAT HAPPEN?  So some idiot was making changes on the assembly line, no one noticed and screwed the Marine Corps?  Or did the Marine Corps request changes almost once every two aircraft.

Doesn't matter.

Something criminal happened here.

I would like an answer before we spend approx 20 mil per airframe to make them the same standard.