Thing is, all of these are ultimately spawns of the same strain of Marxist socialist thought that originated in Russia with the Bolsheviks. Other, less authoritarian varieties, didn't make it for the simple reason that it was suppressed by either capitalists or by authoritarian socialists - like Luxembourgists in Germany, or like anarchists in USSR and republican Spain.

So the only conclusion that can be derived from this is that "Marxism-Leninism" inevitably leads to totalitarianism and poverty. Which is fair enough, but it doesn't really say anything about other varieties of socialism, especially the non-Marxist ones. Are you familiar with the Zapatistas, for example?