I would contest that the bolded assertion, on which the rest of your position relies, is in fact false. In genuine proletarian revolutions- a distinct social phenomenon from an ideologically communist revolution- the leading organs of working class power have always been radically democratic in character- soviets, factory councils, and so on- which have more than proven themselves entirely capable of carrying out the democratic expropriation of the exploiting classes. The concentration of political power into the hands of a party elite represents not revolution but counter-revolution, and the struggle of workers against the concentration of power into a party-state is a further incarnation of class struggle.
Also, I'll elaborate on my distinction between a "proletarian revolution" and a "communist revolution", because it's important in establishing a properly Marxist understanding of the events of the 20th century. For Marx, revolution is not something which is made by a party of intellectuals, a chronologically discrete quest which is consciously embarked upon, but something which emerges organically out of a process class struggle that is being carried on even as we speak. It emerges when the struggle between workers and capitalist, between labour and capital, has reached such a point where the existing political framework is no longer sufficient for the workers to advance their interests, and so loses the ability to contain class struggle. This is what happened in Russia in 1917, what happened in Germany and Hungary in 1919, what happened in Spain in 1936, and what began to happen in France and in Czechoslovakia in 1968. What happened in Poland in 1945 was the imposition of a nominally "socialist" regime by an external power, what happened in China in 1949 was the seizure of the state by a party of populist intellectuals supported by the peasantry, and what happened in Cuba in 1959 was a fairly run-of-the-mill radical nationalist revolution whose leading figures later adopted the form of Soviet "socialism" for largely cynical reasons. In none of these cases did revolution emerge naturally, in none of these cases was the working class a primary actor (and when it attempted to act, it was repressed, often brutally), and so in no case can these be considered representative of what we advocate.
As such, to talk about "communist revolution" in such a manner is to effectively depart from a Marxist analysis of history. Marx was no insurrectionary utopian, no idealistic Blanquist, and neither are we. Such events must be viewed in a proper historical context, in all the messy complexity which that implies, and not simply as the product of certain ideas being "bad" or "dangerous" ideas. That doesn't mean that we can disregard their ideological content, that we can casually distance ourselves from the very real influence of Marx and Marxism in those revolutions, or at least those which were not forcibly imposed by an outside power, but that we cannot treat those ideas as existing in some transcendent ideological space removed from the material, social and political reality of the era.
Thanks for taking the time to reply. Cheesy points out that my question has been asked/answered multiple timesprior, but I don't post here much as you can see by my total post count. An FAQ/index would definitely be nice.
Okay, so you say that the true revolution emerges organically as a result of the existing political framework being unable to advance worker interests. you cite 1917 revolution in Russia. What do you think went wrong? the end result decades later obviously did not advance worker interests but left things as bad or worse than when the tsar was in charge.