Why is Marxism so popular?

Marxism is Hegelism extended.

The philosopher Hegel had propounded a revolutionary scheme ... Change, according to Hegel, was the rule of life. Every idea, every force, irrepressibly bred its opposite, and the two merged into a “unity” that in turn produced its own contradiction. And history, said Hegel, was nothing but the expression of this flux of conflicting and resolving ideas and forces. Change—dialectical change—was immanent in human affairs. With one exception: when it came to the Prussian state, the rules no longer applied; the Prussian government, said Hegel, was like “a veritable earthly god.” (81)

To summarize, everything changes, except my god, my system, my idea, my product, etc. This is the best possible marketing scheme.

Today, Marxism dominates China, cultural Marxism (Marxism without mentioning Marx too much) dominates the rest of the world.

Many popular theories, such as those by Keynes and Kant, share the same trait. For Keynes, there exists optimal equilibrium state. But the real world is often in various disequilibrium. The government (God) needs to push the society toward the equilibrium state from time to time. For Kant, it is “the starry heavens above me and the moral law within me.” The starry heavens above me may change all the time. But moral law within me is fixed a priori.

Evolutionary theory describes the world more accurately. But for a true evolutionary theory, there is no allowance for someone’s pet project. Hence, evolutionary theory, or the so called social Darwinism, is viciously attacked by all schools, religious or secular.