The traditional view is that the Qin Dynasty fell due to harsh rule of law and endless violence. Based on various opinions, I think the reasons are as follows:
1. After Qin’s rule of law was implemented for more than 100 years, it itself has gradually become rigid. First, the historical records of Chen Sheng's family record that Chen Sheng and Wu Guang were beheaded because they delayed the garrison period, and Chen Sheng and Wu Guang rebelled. However, heavy rain should be a very powerful reason for exemption or reduction of liability, but Chen Sheng and Wu Guang do not think this is possible. Chinese scholar Ning Hanlin once pointed out: The fault of the Qin Dynasty's criminal law is that it does not distinguish between circumstances. As long as the consequences stipulated in the criminal law occur, they will be punished.
2. After Qin conquered the six kingdoms, the situation facing the country changed significantly. The system that used to be effective in one corner cannot blossom across the country. It can be seen from the border guards of Chen Sheng and Wu Guang. During the Spring and Autumn Period and the Warring States Period, the country's territory was small, and the people's journey to and from the border was short, and the time spent guarding the border was not long. But after the Qin Dynasty, the country became too big, and problems appeared in this system. The Han Dynasty learned the lessons of the Qin Dynasty and allowed the people to use money to guard the border (those who spend 300 Wen to hire someone to guard the border on their behalf are called "Guo Geng", and those who guard the border themselves are called "Jian Geng")
3. The officials of the Qin Dynasty enforced the law too harshly. Qin is a farming and warfare country that rewards military merit. The martial law system that was supposed to end soon after unification was extended indefinitely. Most of the local officials in the Qin Dynasty were soldiers (for example, the general who destroyed Han was called Nei Shiteng, who later became Qin's defender of Han). They lacked the proper quality of law enforcement and often used rough methods. For example, the two lieutenants who escorted Chen Sheng and Wu Guang were "Wu Guang Anggui Lieutenant" and "Wei Guo Shiguang". Because of this, after Chen Sheng's uprising, "all prefectures and counties who tortured Qin officials punished their chief officials and killed them in response to Chen She." Some Qin officials had even expressed their intention to follow the uprising and instead attack Qin (such as Wu Shouling), the people still did not forgive them.
4. The failure of the Qin government and the lack of local force. Chen Sheng and Wu Guang were just a group of outlaws after the uprising. However, after the uprising, such outlaws, with hundreds of people, were able to "attack Daze Township, take it back and attack Qi. Under Qi, they ordered Fuli Renge Ying sent troops to the east of Qi and attacked Qi, Feng, Ku, Zhe and Qiao. "This shows the failure of the Qin Dynasty's government and the lack of local force.
5. Judging from the fact that Chen Sheng and Wu Guang used Fu Su and Xiang Yan as their rallying cry (and did not care that the latter's country was destroyed by the former's father), it is obvious that the people just hate those officials and harsh government. He has no special dislike for the Qin Dynasty, and his political propaganda failed.
6. The corvee system in the Qin Dynasty was too serious and was accompanied by discrimination between ethnic groups. After a little observation, we found that Liu Bang, Xiang Yu, Yingbu and other heroes in the late Qin Dynasty were almost all from Guandong, and almost all of them had the experience of serving in Guanzhong. Judging from the current excavations of the tiles of migrant workers who built the tomb next to the First Emperor's mausoleum, almost all of the recorded birthplaces were counties in the Guandong region. The Qin Dynasty built straight roads and conquered the Xiongnu Baiyue. Most of the food and grass they needed came from the Guandong region. I remember one issue of Exploration and Discovery said that the food and grass used by the Qin Dynasty to attack the Xiongnu came from Qi. The convoys transporting food had to cross the Taihang Mountains twice and the Yellow River three times. Only 1 stone out of every 65.5 stones of grain could reach the front line. This shows the extent to which the Kanto economy was plundered.
7. Qin’s unification process had a colonial conquest-like policy, which caused the Guandong people to suffer great suffering. Whenever the Qin State conquers a land, it will seize it and move the Qin people to live there. Historical Records of the Qin Dynasty records that in the 21st year of the Qin Dynasty, King Zhaoxiang of Qin "attacked Wei Hanei by mistake. Wei offered Anyi, and Qin sent out his people, recruited people to move to Hedong, granted them titles, and pardoned the guilty and moved them"; "In the 26th year, the guilty were pardoned and moved to Rang." Hou Ya returned to the prime minister. In the 27th year, he mistakenly attacked Chu and moved to Nanyang. In the 34th year, Qin, Wei and Han Shangyong became a county, and Nanyang exempted officials and moved to Nanyang. This is also what is mentioned above. It is said that the heroes of the late Qin Dynasty, such as Liu Bang, Xiang Yu, and Yingbu, were almost all from Guandong, and almost all of them had the experience of serving in the Guanzhong area. Moreover, the people in the Guanzhong area of ??the Qin State only suffered from strict laws. Instead of suffering from corvee labor, their economy did not suffer very big losses. This is why after the great uprising in the late Qin Dynasty, all the flashpoints were in Guandong, but the Guanzhong area never sent out a spark; Liu Bang's entry into the Guanzhong was just a matter of time. The three chapters of the agreement made the people happy; during the Chu-Han War, Liu Bang occupied Guanzhong and had abundant food.
8 This was the change in the quality of Qin's leaders, which emphasized the rule of law. The rule of law is based on monarchy, and the emperor's personal qualities played a very important role in the development of the country. Obviously, after the death of Qin Shihuang, the talents of the second emperor who came to the throne were far inferior to that of Qin Shihuang (although according to historical records, the second emperor ascended the throne). In the following spring, he traveled to counties and counties, and within 4 months he traveled east to Zhejiang and north to the Bohai Sea and back to Taihang. If this record is true, this undoubtedly created a high-speed record under ancient traffic conditions.
This seems to show that Qin II is not an incompetent king, but obviously, even so, his personal experience and enthusiasm are obviously not enough to take on the important task)