"Yet there is no mention of questioning the validity of the very notion of
'procurement' itself"
Don't confuse artifacts and processes that meet requirements for cost
transactions with software design. The inability of software analysts
to grasp the fundamentals of logistics is one of the drivers for the
churn in software tools and products.
The essence of waterfall is not seeing over the wall. Programmers in
agile environments make the mistake of thinking they are the center of
the transactions. They are not. They are an engine, not a steering
wheel or a brake.