I'm curious whether it's the author's contention that the signatories of the Agile Manifesto thought that the ideas they were championing went back only a few years, and they had no idea they went back at least 30. In particular

> All of these things were later claimed as Agile innovations

Are there some references that demonstrate that? [EDIT: that the signatories thought they were their own innovations]

And if so, is that a bad thing? Ideas are repeatedly rediscovered. This article isn't called "Saying goodbye to Royce, Bell and Thayer", and I'm wondering why not.