It's interesting that failed communist regimes often seem to be succeeded by kleptocracies. I wonder if any political scientists have studied this and can explain why.
That's not exactly explanatory, though. Any time a position is powerful or enriching well beyond the extent to which it serves others, the people optimizing to seek out and attain those positions are those who want the power and wealth, rather than those who care about the organization's mission. For those people, the original mission is, at best, a distraction, and at worst actively antithetical to their personal goals.
Communism does not produce globally competitive industries. So the only thing left to do is either to steal and pillage what is left or work in an industry that has local demand like food or energy. Those tend not to be very attractive jobs.