Why did the Liling incident destroy the historical records?

Because after the Liling incident, Sima Qian accepted the imprisonment, and when writing historical records, he looked at and interpreted history in an alternative capacity.

Sima Qian is a very talented person. After accepting castration, Sima Qian was forced to treat people, life and history from the lowest social identity of a despised society. After being tortured both mentally and physically, he changed Sima Qian's view of life and death. He fully affirmed the legitimacy of people's pursuit of wealth and completed the historical records handed down from generation to generation in an alternative capacity.

Event background:

In the summer of the second year of Tianhan, Emperor Wu of the Han Dynasty sent his favorite brother, general Li Guangli, to lead a crusade against Xiongnu, and sent Li Guang's grandson, Don't escort Li Ling to Li Guangli to escort the trench. Li Ling led five thousand foot soldiers out of Juyan, and went deep into Jishan alone, suffering from sweat. Xiongnu besieged Li Ling with 80,000 cavalry.

After eight days and nights of fighting, Li Ling killed more than 10,000 Huns, but because he could not get the support of the main force, he ran out of ammunition and was unfortunately captured and surrendered. Sima Qian interceded for him and was sentenced to prison.