In ancient times, punishment was very severe, such as conspiracy against such a major crime, just beheading is not enough for the common people to be indignant, but also to connect the nine tribes, that is, to implicate their families. It is conceivable that the cost of such a great crime as rebellion is also very high, but there are often many powerful ministers who will desperately take risks and launch mutinies in order to compete for the peak of power.

In fact, for rebellion, the most crucial issue is to grasp military power. But from our modern point of view, although the military power is in the hands of the military commanders of various places, in fact, the soldiers are loyal to their country and to their emperors. So why, when the local military commanders rebelled, the soldiers did not think of protecting the emperor, but followed their generals and participated in the military coup?
The emperor was incompetent and the people's livelihood was difficult
Whether he is a soldier or a farmer, he is one of the people of the country, and his truest wish is to live and work in peace and contentment. However, each generation of male lords, although they collect taxes from the peasants to strengthen their own armies, but the excess money, they still hope to take from the people and use it for the people.
The emperor's heart is centered on the people, then he can certainly create a prosperous world, which seems to be an immutable law. Under such circumstances, even if the local military commander wants to launch a military coup, it is a very difficult thing. The people all said that the emperor was good, and the significance of their rebellion was no longer there.
Therefore, generally allowing soldiers to take the initiative to follow the general to start a military coup, then one of the possibilities is that the emperor is too incompetent, so that the people's livelihood is difficult, everyone can not live happily, and a revolutionary change is needed to change this situation. King Shang is one such example.
In the early days of his reign, the King of Shang was actually a very talented king, and the people of the Shang Dynasty were still living and working in peace and contentment. However, in the later period of his reign, the King of Shang made a mistake that almost all the late kings had, that is, indulging in female sex and building a lot of civil engineering, which led to the people's lack of livelihood, so in the end everyone came to oppose him.
The news is closed, and the king is not known
In ancient times, unlike we now have very advanced imaging equipment, every one of us who has access to high technology will know very well what important people look like. However, in ancient times, there was not so much advanced equipment, and even some soldiers did not know what the emperor looked like for a lifetime.
Faced with this situation, the commander of the soldiers is the emperor in their minds. According to discipline in the army, that is absolute obedience to orders, so a mutiny, often the soldiers are not aware. Even if many politically minded soldiers discover that this is a military uprising, if they choose to resist, they will face a situation of enemy and widowhood, and it is very likely that they will sacrifice their lives to the flag.
Therefore, in the absolute environment of such a closed message, the soldiers are like pawns in the hands of the general, they only need to resolutely carry out the order, and other things are generally not asked. Therefore, once the mutiny is launched, the lives of the soldiers are already in a dilemma.
Fortunately, in general, kings are very sympathetic to soldiers, they are just pawns, as long as they surrender, they will be treated with good leniency. Just like during the Ming Dynasty's Zhu Zhanji period, in the campaign to pacify his second uncle, he quelled the rebellion with great tolerance, and in the end the soldiers survived, and there were no Nine Tribes.
Desire for power, glory of the ancestors
Soldiers are the lowest beings in the army, but this does not mean that they are only satisfied with themselves as a pawn. Just like the rebels, their highest goal is to stand at the peak of power, that is, to become the emperor of the time, to satisfy their own selfish desires. The same is true of soldiers who are soldiers, and soldiers who do not want to be generals are not good soldiers.
In the face of their own desires, as long as they are people, it is difficult for them to control themselves, so when this desire appears, coupled with a suitable time, there is a scene of soldiers following the general to rebel. After all, since the Qin Dynasty, military merit can be said to be the easiest and most dangerous opportunity to get people to the throne.
Therefore, in the face of the glory of the ancestors, often the leader of the order, they only need to make meritorious achievements, for the generals, the leaders of the world. Once this move is successful, when discussing merits and rewards, it is very likely that he will be promoted, so as to honor his ancestors.
At this point, we can see from the official system of the Qin Dynasty how tempting military merit is to people. It can be said that the official system of the military merit system made the Qin State once become the hegemon of the Warring States, and at the same time laid a solid foundation for the Qin State to sweep away the six and unify the world.
epilogue
In fact, for rebellion, a large part of it is because of people's pursuit of power or selfish desires, so as to launch a unilateral war. Of course, there is no shortage of dynastic changes caused by the fainting of the king. But no matter which ideology, the most fundamental reason is still caused by people's pursuit of power.
References: "History of History", "History of Ming"