The liberation of workes from capitalist oppression.
...into the oppression of the state. Even if it isn't social oppression, it's still oppression. Slavery to the downtrodden.
An impossible ideal. Even if you equalized people's economic status, people aren't equal - equal in rights, sure, but not equal in ability. Some people are smarter, stronger, more attractive, or have some other quality that gives them an advantage. Heck, some people merely have the advantage of being motivated. The only way to equalize things is to bring such people down - it's not possible to bring others up, because it goes beyond their abilities.
Is it fair to bring down the strong for the sake of the weak? Do those born with ability not have the right to use their abilities for their own benefit?
And what is so great about equality? Outside of equal rights, I don't see the need for equality - I see the need to let people excel, to use their abilities. We don't look up to the weak for inspiration - we look to the strong. The strong motivate us, we want to be like them. We want to be great. We want to excel. They drive us to improve ourselves.
The desire to make all equal is the desire for equal mediocrity.