I agree that monetarism created a bear pit for us all to stumble into. I would also argue that was always apparent to the astute scholar but who listens to the astute scholar when there is a dollar to be swindled? Maybe it is the article's argument but Monetarism is not accepted as part of Keynesian theory. Monetary policy is part of Keynesianism but the monetarists are a separate (and opposing) school. Happy to be corrected though.
"Monetarist economics is Milton Friedman's direct criticism of Keynesian economics theory, formulated by John Maynard Keynes. Simply put, the difference between these theories is that monetarist economics involves the control of money in the economy, while Keynesian economics involves government expenditures. Monetarists believe in controlling the supply of money that flows into the economy while allowing the rest of the market to fix itself. In contrast, Keynesian economists believe that a troubled economy continues in a downward spiral unless an intervention drives consumers to buy more goods and services." https://www.investopedia.com/ask/answers/012615/what-difference-between-keynesian-economics-and-monetarist-economics.asp
