Why do some people don't trust those fortune tellers, but they still have to count?

In fact, as we all know, fortune telling by fans is a part of Zhouyi. Denying the fortune-telling of fans means denying Zhouyi, and then Confucius became a liar. Because this book was written by Confucius and arranged by him. There is also the fact that Fan's fortune-telling has existed since ancient times. Although there are few accurate people, there is a group after all. If it was a lie, he would have been escaped by society. It won't spread to order. You can go to bookstores and stalls to sell books. Do you think that there are the most fortune-telling books for fans and it is best to sell them? Why?