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 Citadel, a vast ancient multispecies atrium made by mysterious ancient beings that left behind mysterious caretakers, is a fucking 90s mall in space.
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.
That would be clever but I doubt that was the conscious intention. Their goals were for species to develop on predictable routes that could be exploited later.