MoI being an accessible entry to CAD is just a side-effect of an overall non intrusive user experience that fosters on the fly concepting and flow, in my opinion. That's a much greater value than training wheels, at least for illustrators and concept artists that use 3D to get imagery. MoI's fluidity allows for a state very close to the one I get during painting, but that is just a very biased opinion of someone that started CAD with MoI and is not looking to build real things.