Which is tragic because it is a neoclassical fiction book misleading millions of students. Anyone who is really interested in the history of economic thought will avoid that book for anything other than being a reference of the theoretical position of the neoclassical synthesis.
Every economic model is fiction to some degree, what matters is the usefulness of the models to make policy decisions or predict outcomes. One can branch off into heterodox schools of thought like Austrian, Marxism, Chicago, or Behavioral... but students need to be grounded in the field's consensus to be able to know how to speak intelligibly across these areas if they're to have any effectiveness.
"what matters is the usefulness of the models to make policy decisions or predict outcomes"
Correct and the equilibrium models used by the mainstream fail to do that in every possible way which is no wonder because the economy is a complex system that is never in equilibrium (non-equilibrium is basically the defining feature of our economy). Failing to describe the economy as a complex system failing to explain how the monetary system works are unforgivable errors and shouldn't be tought to studends for anything but showing them how fallacious thinking can lead us astray. The neoclassical Keynesian synthesis is one big fallacy of composition, it should never have gotten so much traction and the only reason it dominates is that it is politically useful to a few people on top. But it definitely doesn't model the economy in a useful way.