In the end, most of your ideas about economics are Rogoff and Reinhart writ large. Namely, dubious assumptions motivated by an agenda are supported by supposed facts whose math doesn't bear close examination. The Sixties were a time of war, assassination, Cold War, inflation, gold drains.
The Sixties also led inexorably into the Seventies, whose infamous stagflation refuted Keynesianism.
The attempted revival is a fad inspired by desperation. Are there counterfactual arguments that a combination of misfortunes, crimes and errors prevented a better outcome for Keynesian policies? To be sure, just as there are stronger
counterfactual arguments about the possible outcomes for socialist economies.
I have a much more interesting post about Greece to reconstruct, but real life has slowed it. This is to keep the thread alive til I can rewrite it.