How can one explain that the hopes for a revolution without blood and tears were unsuccessful?

You can consider this issue on the example of tsarist Russia. At its core, this state was an empire. Any empire relies on the military. The empire exists at the expense of the conquest and plunder of the surrounding territories, the appropriation of the results of someone else’s labor, the exploitation of the labor of slaves. And the position of the workers and peasants, especially, did not go far from the position of the Roman slaves. Repeatedly the authorities drove these people to the slaughter in military operations. At the same time, the authorities never fully fulfilled their promises. In such a state, revolution is only possible “through blood and death.”