I still don't understand why the magnetization or the energy of the Ising model should be "unnecessary internal implementation functions" when they are the actu

I still don't understand why the magnetization or the energy of the Ising model should be "unnecessary internal implementation functions" when they are the actual outputs of the model. Thinking more about it, the example is (almost) a value object class. I don't think this is well-chosen for making a point about bloated classes.