For instance, the Civ games are basically Whig History: The Game, presenting liberal capitalism as the ideal end point for all societies. It even includes uncivilized "barbarian tribes" whose sole purpose is to be exterminated so you can take their land for the glory of capitalism.
The only handwave you could maybe make with that is
spoiler
Maybe the Reapers wanted everyone to be capitalist? They did plant technology all over the galaxy so that organic societies developed along the paths they wanted.
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