My take - Limited conceptual capabilities due to exclusive Nurbs choice.

 From:  black mariah (BLACK_MARIAH)
Not trying to sound like an ass (okay, maybe a LITTLE) but if you're comparing an unfinished single-purpose app to something like XSI... you need to see your doctor about have a cranial-rectal extraction done.

Think of MoI as being the NURBS equivalent of Silo.