What was the reason why Wu Kai in Tiangong was not valued by scholars at that time?

Because there is a strong sense of "distinguishing between China and foreign countries" in a large number of ancient books in China, in order to consolidate the rule as an alien and eliminate the subjective consciousness of the Han nationality, the ancient books in China were centralized, inspected, revised and destroyed, which is also commonly known as the "Sikuquanshu". Among them, those that were considered unfavorable to the Qing Dynasty were modified or destroyed. Tiangong Kaiwu was destroyed by the thought of "anti-Manchu". Later, Wu Kai in Tiangong was reprinted in China in the early Ming Dynasty. -"Heavenly Creations" was slightly extracted from "Integration of Ancient and Modern Books", but it was lost in China because of the suppression of anti-Qing thoughts in the revision of Sikuquanshu. At Tianyi Pavilion in Ningbo, Zhejiang Province, its first engraving has been preserved so far. However, it was not publicly issued in the Qing Dynasty and was widely circulated.