: [T]his cannot be the same world as it was when Marx was alive and "workers of the world unite!" was not only revolutionary, but not yet cliched. And so, I remain uncertain that Marxism remains a viable alternative to today's capitalism. It may need to be modernized, in other words.
Even a cursory glance at either Capital or The Communist Manifesto will demonstrate that Marx's theoretical model of capitalism was, in fact, globally hegemonic monopoly capitalism, i.e. capitalism as it stands NOW. When Marx wrote, capital was a strong but geographically small challenger to the mass of continents that lived under feudal, semi-feudal, and primitive capitalistic economic conditions. His work is actually MORE pertinent to today's social relations.
And, to address your post's title, I consider cynicism to be an integral component in revolutionary development. Who's more cynical about capital than a Marxist?