Why didn't the king kill the Dugu family to prevent them from usurping the throne after the "Dugu World" was predicted?

There is a prophecy of "Dugu Tianxia" in "Dugu Tianxia", but the king didn't kill Dugu's family at that time, because the king went to find the daughter of Dugu's family to be the queen, and the king loved the queen deeply. The king thinks that the children born to the king are the grandchildren of the Dugu family, and they are related by blood, and his son is the realization of this prophecy, so his son will definitely inform future generations to manage it better.

The drama "Alone in the World" tells that the queen loves her husband very much and does not allow her husband to like girls other than her. Once the emperor fell in love with a little maid-in-waiting, but after being discovered by Queen Dugu, he tortured the girl to death. The emperor was very sad, but she didn't blame the queen, just silently sad.

Of course, Emperor Wendi of Sui also loved his queen. During his reign as emperor, he had only one concubine, and the rest of the harem were all imaginary courtyards. There are no other concubines. Of course, the emperor has always believed in the prophecy of "the world is lonely" and is convinced that the children born to the queen are the grandchildren of the Dugu family. Therefore, his son will make great achievements in the future, the country will be rich and strong, and the people will live and work in peace and contentment. This is why the emperor did not kill the Dugu family, but was mean to the Dugu family.

In fact, this prediction of "the world is the only one in the world" is a false prediction in the final analysis, because Emperor Wendi only loved the queen, which led to the emperor's less blood, only five sons, and among these five sons, there were even fewer sons who could govern the country. Therefore, after Emperor Wendi abdicated, he passed the position on to his sons, and the sons could not control the situation of the country at all, which led to the early collapse of the Sui Dynasty.