The problem with calling the movie an allegory is that allegory doesn’t tell you anything you didn’t already know, and it hides the thing you didn’t realize it was persuading you of. Allegories are closed ecologies. If Snowpiercer is a movie about capitalism, then we already know what it is, and says, because we already know what we know about capitalism. If you think a death-train of the damned in a post-apocalyptic hellscape is an allegory about capitalism, then it’s because you think capitalism is a death-train of the damned in a post-apocalyptic hellscape. But if everyone knows that the train is an allegory for industrial capitalism—and everybody certainly seems to—then it’s not a secret, and not the kind of allegory Jameson was talking about when he described anti-capitalism as our political unconscious.
It’s anything but the kind of unspeakable, repressed truth that we all pretend not to know, even to ourselves; the fact that the train is capitalism is the thing we allow ourselves to talk about because we’re afraid to talk about the real thing it is, which is death, our fear of death, and our desire for the thing we fear.