Whether or not "true capitalism" or "true socialism" have ever existed is completely irrelevant. Not everyone needs to become a capitalist or a socialist for us to see why socialist market intervention violates the consent of individuals and results in the opposite of its intended effect, or why uninhibited consensual exchange only happens when the consenting parties involved all expect to benefit (making it inherently win-win ).
Similarly, not everyone in the world needs to become a rapist or abstain from rape to prove that rape is a morally wrong, imprudent way of starting a family.
It is the collectivist, socialist, interventionist aspect of mixed economies which cause and exacerbate the severity of complete market failures. When individuals abstain from exchange, it's because they don't expect to benefit. Using the state to force an exchange to happen absent consent (which usually happens by price fixing) does not change the fact that parties withholding consent don't experience the exchange as a benefit but rather as a loss.
Mixed economies are rigged against those who threaten the competition averse by being productive and innovative. In a complex economy, market allocation of resources at all stages of production is the only way in which consumer demand can be balanced with supply such that the economic calculation problem is avoided. Every next intervention designed to protect someone from the outcome of market competition creates two more problems which, from the perspective of the interventionist, necessitates more intervention, the continued implementation of which distorts prices and divorces consumer demand from supply (which leads to resource misallocation and supply shortages).
That's why mixed economies lead to outright socialism and communism, both of which lead to mass starvation. The market doesn't deserve to be blamed for that.
It's not the market's fault that socialist market interventionism sucks so much ass.
I'm Jared Howe! I'm a Voluntaryist hip hop artist and professional technical editor/writer with a passion for Austrian economics and universal ethics. You can catch my podcast every Friday on the the Seeds of Liberty Podcast Network.
