Author here.

So one of the main points in this massive, 700 word Treatise (which I do hope you will find the time to read) was that nothing Agile practitioners slapped their label onto was actually novel.

Why re-invent agile, when agile itself was just a reinvention by "the kids" (your words, not mine) of things people in the 1970s already knew?

One might as well go straight to the 1970s directly.