Welcome to the world of tomorrow
Trevor, this is a good article and would have been even better two or three years ago. Unfortunately the "big players" already got there in terms of enterprise level virtualization of white box storage, ingestion of existing storage and server based SAN & NAS. Take a look at Dell EMC ViPR currently running version 3.x and scaleIO pretty much the same. Massively scalable technologies already in enterprise customers delivering what you are talking about with a level of maturity that startups cannot match.
The software defined component is important because you still require the means to control the "whitebox" technology to deliver the services that you need. To do this you need a virtual array to mimic the data services of a fully functional physical storage array, particularly in the NAS arena. The virtual array also offers QoS, encryption and data services like tiering and compression.
As I said nice article, but, it is not a view of the future but of current reality.