Various kinds of divination exist with different scope and for different purpose. Take an analogy. Suppose x is the name of a predictable event, affair, person or place. Astrology is similar to a film (motion picture) of x, palmistry is image of x, tarot is like sketch of x. So what is more understandable and helpful to you: a film, image or sketch? Obviously astrology can qualitatively and quantitatively address humans’ affairs far better than other divinational arts.