The goal of capitalism, not just the utopias generated from within it, is to eliminate every boundary, including that of class. And that doesn't mean that there aren't rich and poor people, but the secretly humanist idea of class in Marxism is to universally project an economic subjectivity, in order to give economics a cultural value. Race and gender is an aspect of who we are, as is how we are educated and what kinds of people we are exposed to-- the name that leftists accept for the latter two are "class," but one's production role is just as easy to make abstract as someone's skin color or gender-- much easier, perhaps.
What is called "the common" is not a lost narginal zone of freedom. It is something that nobody knew how to make money from until homeless people and poor people and inventors and anarchists showed them how.
I believe in "rich" and "middle" and "poor," emphatically, but I really feel like there's absolutely no aspect of one's identity that capitalism will not exploit more than another. That's the deeper Foucault breakthrough-- not "prisons are the source of all evil," but more like "prisons used to do this one thing, but now they are where capitalism invents and manifests a set of values."
Capitalism is a Real on par with the Divine. I find it harder to think outside of capitalism than outside of God, by a long shot. I think this makes God special in a new way.