When it comes to the rise of the Party as an organization of the bureaucrat class in Russia and China, we have to keep in mind that these countries were highly underdeveloped and particularly lacked education, even having an enormous degree of illiteracy and analphabetism. People who can't even read are hardly capable of even just Bourgeois democracy, let alone of managing a democratic economy. So the Party and its bureaucracy had to take up the tasks that should have been done by the people themselves, but that way, it indeed started to form a new ruling class. It's a tragedy of history, but that doesn't necessarily mean that it would also happen if a Socialist revolution happened in a First-World country. Essentially, the big problem of the Russian Revolution was that it happened in Russia.