From my point of view, EP finally threw a true clunker. This story just didn't work for me in any way.
The fundamental premise just wasn't plausible -- Karl Marx ignites a future revolution? Hundreds of years after his ideas have been throughly debated, explored, tried out, etc? Intellectually, he'd be pitted against people who had seen his playbook for generations. And we're supposed to buy the idea that his 19th-century rhetorical skills will suddenly set the world on fire? In a culture of which he has virtually no knowledge? There's just no way to make all that work, in my mind.
Not to mention the idea that a government would try to put down an internal rebellion by using atomic weapons? As Heinlein said right after WWII -- it would be like trying to keep order in a nursurey with a pistol. Possibly the most extreme imaginable case of "destroying the village in order to save it." And not one likely to fly...
As others mentioned, the characters were decidedly un-compelling -- cardboard cutouts, mostly. We don't hear much about their motivations, and there are so many of them relative to story length, that we don't get to see much of them in action, and what action we do see reveals little. Aside from the fact that they are "radical" we know nothing about the details of the ideology that motivates their actions.
The plot lacks much detail, and most of the action reads like a schematic. Aside from the atomic bombs at the end, we know nothing about how the revolution takes hold, the course of the conflict, how the government resists, the techniques used by the revolutionaries, etc.
So no, I don't "get it." But I don't think it's ideological bias (I'm a bit of a lefty, anyway) but because it just wasn't a very good story.
I liked the song at the end, though. And I missed the feedback section.