So Max Cady was also an expert in book reading?

In a scene where he met at school Juliette Lewis' character (its controversies briefly put aside) - how was he so confident that the ending was in it "almost like a COP OUT" whereas Lewis' character liked it and thought it was almost like a "pilgrimage"?

And in what exact ways was it a "cop out" to him and not a satisfying or even a normal ending?