Conspiracy theories require more than one participant, Apple are essentially a single party and have nobody to conspire with on their product lines. Having used Mac OS based computers since the late 1980s I have observed Apple's design and production methodology for quite a while.
Since the iMac first appeared in 1998 Apple have had a knack of designing products which allowed them to directly control the hardware development very closely and almost without any other party having a say in how their products are modified. Only where similarities to PC hardware existed did Apple have less control over what you could add yourself.
My first iMac was upgradeable in many ways, I added a Sonnet Harmoni G3 600 MHz daughter card, 80 GB HDD and firewire to it along with a Voodoo 2 GPU mezzanine card. It accepted 512mb of RAM when Apple claimed the max memory was 128 MB.
Since then Apple's grip has tightened on the expansion of their kit, the "classic" Mac Pro being the main exception. With virtually all the adjustments we have made to Mac Pro towers since 2006 being outside of Apple's control, this machine more than any other has been the opposite of Apple's sealed unit architecture which proliferates throughout the rest of their product range. If you look at iPhone, iPad, iPod, iMac and Macbook design since 2010 all these products are much harder to modify, if not impossible to in some respects. The nMP fits this profile far more than a large tower filled with PCI-E ports and other PC friendly connections.
The nMP re-establishes Apple's complete separation of hardware from the PC parts sphere just as effectively as welding RAM to the logic board, using proprietary SSD drives and gluing batteries into Macbooks ends any ideas of user upgrades.
This is a good philosophy for Apple and will make sure that the majority of revenue from their professional hardware goes to them and not to 3rd parties who sell PC parts that just happen to fit.
I don't think this is a conspiracy I think it is a commercial strategy and I think it will work.
http://youtu.be/XDISI2IL5Ns