Mainly Meng Tian and Fu Su are too irrational, too naive and too simple to think about officialdom. Fu Su, the eldest son, was filial and did not doubt his father's death. Although Meng Tian had doubts about this matter and advised his eldest son Fu Su, Fu Su was bent on dying after receiving the letter, and Meng Tian could not stop him. After Fu Su's death, Meng Tian even doubted the authenticity of the letter and finally committed suicide by taking poison.

Of course, the death of the eldest son Fu Su was due to the lack of proper communication between Fu Su and his father Qin Shihuang, which made it difficult for the eldest son Fu Su to understand his father Qin Shihuang's mind. As we all know, Fu Su, the eldest son, is honest and kind, with a kind heart and unyielding personality, so some decisions of his father Qin Shihuang are inevitably in conflict, while Fu Su, the eldest son, is too naive. So, in a rage, Qin Shihuang arranged for his eldest son Fu Su to be with general Meng Tian, hoping that his eldest son Fu Su would mature through Meng Tian's education so that he could control the country in the future. However, Fu Su, the eldest son, didn't understand what his father had done and thought that his father didn't like him, which also led to Fu Su,

Secondly, although Fu Su, the eldest son, and Meng Tiandian had 300,000 soldiers at that time, Meng Tianyi handed over the military power when he received the imperial edict, so even if Meng Tiandian doubted the authenticity of the imperial edict, Meng Tiandian, who had no military power, was no different from a tiger with his teeth pulled out, and became a lamb to be slaughtered. Of course, when Meng Tian surrendered the relieving, he just wanted to delay some time, hoping that Qin Shihuang could make a new imperial edict, but unexpectedly, Qin Shihuang was dead, and the imperial edict was forged by Zhao Gao and Reese.

Generally speaking, the eldest sons Fu Su and Meng Tian died simply because they never imagined that under the coercion and inducement of Qin Shihuang, some people dared to forge imperial edicts and impose the death penalty on court ministers and governors. Of course, these two people are too naive to handle things and ignore the crisis in officialdom.