Why do most people think the Book of Changes is a fortune-telling book? As a roadside fortune teller?

Because Zhouyi has four functions: image, number, reason and karma. Divination is one of the four functions, because the Book of Changes has a great reputation. No matter who reads it or not, as long as they can read divination, most people say that they have learned the Book of Changes, especially the charlatans on the roadside, which gives people the feeling that they have read it as fortune tellers.