The problem with a Capitalist Utopia is not in the ideas or in the policies, it lies with the simple fact that humans are the ones carrying those policies out. There's a good quote that sums it up: "power corrupts, absolute power corrupts absolutely." Some group of people will be in charge, and that group of people will exploit the rest. Capitalism works great for small groups, but breaks down at the population level.

Works both ways, so you are not actually proving anything with your statement except showing your ideological blind spot.

I'm not arguing for unbridled capitalism, nor am I arguing against socialist policies and checks against the formation of oligarchies. I'm arguing that state control of the economy, such as that which comes about when your population is too spread out and large to make decisions in an efficient manner, is inherently flawed and unsustainable.

And countries like the USSR were not only dictatorships, but virulent military dictatorships.