Are you unfamiliar with capitalism as a theory? Or Ayn Rand? Yes, capitalist utopia. That’s the entire libertarian ethos. Libertarianism is a political framework for governance, pure capitalism is its economic policy.
Don’t get me wrong, the only Libertarianism I’ve ever known is intertwined with Capitalism. But they aren’t the same thing, and I always read BioShock as being a take on Libertarianism specifically.