Because the cookbook approach by itself requires that the questions be as limited as the answers. Going outside the boundaries produces confusion at best, and either an inaccurate reading or no answer at all at worst.
The cookbook approach does have use and merit. You can safely and logically go beyond the cookbook approach and become a genuine Tarot reader (or even a Master Tarot reader) and read without using books at all!
The cookbook approach is a great way to train yourself in the format (Celtic cross format for example) and to learn to read the cards.
Think of it like a trial run to learn the neighborhood. As you go you will slowly take those answers as guides not fact that you find in the book i.e. to define the magician card, the 10 of pentacles, and so on.
You will evolve in time to define each and every card, every line, every color in the picture, every creature. In a years time you will see these cards in the same light as information you learned in a book that helped you communicate better, do better math, yet maintaining dymanicity in your ability to use this knowledge (wisdom is knowledge put into play dynamically).
Let's consider for a moment two questions.The first question is based on the subject of love. This is a common subject, and so every book on Tarot interpretation includes a “love” interpretation. But the second question deals with what would happen if the questioner buys a kayak. It's about kayaks. Where is your cookbook interpretation now?
They might be able to see how to answer such a question if they wanted to know how buying a kayak would affect them financially – money and finances are also a common cookbook subject. But a kayak, you can't read about with the cookbook approach. Not directly.
You take advantage of the strengths of cookbook style interpretations to make it quick and easy to get started reading accurately while teaching you the rest of the subject, and how to read accurately for almost any topic without books or notes. You then start reading immediately, and you learn to read safely, in a sane and rational way.Yes that's right – a logical approach to reading Tarot cards!
In time you will come to realize that the lovers card can tell you when a new crush is coming. Maybe you saw someone and processed the potentials subconsciously and the cards showed you that processing- but the same card can mean something not even related to love. It's what the cards theme is i.e. the lovers card represents the dual nature of sexuality, interest, bonding, and so on. In the Kayak example the lovers card could tell you that you really feel a bond with the sport of Kayaking!