Because the divination is unfavorable. According to the relevant information, Yixiu decided not to live in Kunning Palace because someone in the palace told him fortune-telling and came to the conclusion that "Kunning is unfavorable", but chose Chengqian Palace as his residence. This reflects the prevalence of people's beliefs in divination, Feng Shui, etc. at that time, as well as their emphasis on good and bad luck.