The person who wrote it totally missed the point of the book. She's disappointed because there's no wisdom in the book. Well, of course not. You're supposed to follow the instructions, get enlightened, and become wise. Unfortunately, this reader's misunderstanding is very common.
People think enlightenment is about absorbing wisdom from wise sayings.
Sorry, that's not how it works. The way it works is, the book tells you what to do . The doing makes you wise. One of the reasons a lot of people are confused about this is that some methods for getting enlightened require the student to adopt and hold specified convictions about the mind and universe. In this way, he can realize the Atman, which is Infinite Being, Infinite Wisdom and Infinite Love.