Well, imo the statement holds true with any of the UML -> Agile/Scrum(especially True Scrum, when it is your fault when it not works) and Lean/Kanban substitutions.

I wonder whether they are the same people selling bullets in different shades of silver though the ages, or it could be that the SW business is big enough that we can witness different species develop the same survival strategy of going from host to host and sucking their money out in different niches?