My thought is that they apply a type of Rousseauian “noble savage” when it comes to ex-colonies. They basically believe that poor Third World countries are ruthlessly exploited by the First World and workers in the latter countries are essentially milking off the former and exploiting them. Without the First World, the Third would be very fast in abandoning capitalism. It’s a blatant idealism on the situation of the proletariat of the ‘developing’ and ‘underdeveloped’ world.
Sadly, they are hopelessly ignorant in the actual situation of things on most third world countries (especially Latin America, which is comparatively better off than Africa and South-East Asia). Capitalist relations of production are predominant, and the people themselves are facing the same problems as the First World when it comes to liberals and conservatives, plus all the corruption and political games that hold them back. But if you disagree with them, you are an imperialist.
The only thing Maoism did for socialism besides its own detrimental legacy was Juche and the Khmer Rouge.