A revolution is an insurrection, an act of violence by which one class overthrows another. The students cannot fight against the Communist hard-liners and, at the same time, demand more of their socialist system. That is like fighting half a battle, which always leads to defeat. It becomes a complete failure when the enemy wages total war as the Communists have done. The people are sick of the Communists and their power struggles.
Communism is like a disease.
The student protesters at Tiananmen Square had no power over it because they were infected by its beliefs and practices. At the start of Mao's revolution, Communism was preached as an atheistic solution to all of life's problems. Today, Communism is nothing but a hollow religion. It is a perverted doctrine that solves no problems, but it helps to institutionalize power for the few. During the Cultural Revolution, the people were forced to worship Chairman Mao.