Conversation so far:
What is Neo-Keynesian economics?
Neo-Keynesian economics is a school of macroeconomic thought that was developed in the post-war period from the writings of John Maynard Keynes.
What is Keynesian Analysis?
How did John Maynard Keynes want currency managed?
John Maynard Keynes advocated the use of fiscal and monetary policies to mitigate the adverse effects of economic recessions and depressions.
Were John Maynard Keynes' economic views popular?
John Maynard Keynes's economic thinking only began to achieve close to universal acceptance in the last few years of his life.

Question: What did his critics say?
Self-contained rewrite: What did John Maynard Keynes's critics say about his economic views?