But there are criteria other than efficiency. You might think that if system X is less efficient than system Y, but has (say) greater social justice, then X works better than Y.
Besides, you haven't shown that communism is necessarily less efficient than market capitalism, only that it isn't perfectly efficient; but no system is perfectly efficient anyway. If you had a communist society where individuals didn't waste as much as they do in modern western society, then even if it were quite inefficient when it comes to production and supply, it might still be more efficient overall than our society is.
Without a market mechanism overproduction is innevitable. While its true that overproduction exists in the capitalist system, it reaches absurd heights in a command economy.
Overproduction in the capitalist system is a result from reinvestment. Investors naturally reinforce their enterprises when they are profitable, and unless demand increases to keep pace, you create a problem of overproduction.
In a planned economy, you almost immediately create a system of overproduction. A capitalist can only expand his operations as far as his profit margins allow. With profit removed from the system, it becomes a question of increasing production as much as possible with the resources alotted by the state. Because there is no market mechanism, goods are merely distributed, there is never a reason to halt expansion of production. While making more goods sounds great, this leads innevitably to economic irrationality and inneficiency, as people only desire a certain product so much, and anything made beyond that is just elaborate waste. This is why you see pictures from the Soviet Union where super markets are filled with things such as vinegar. The problem is not just the underproduction of staple foods; this is intertwined with the overproduction of another product, such as vinegar, which is then cutting into the production of other goods.
But ah! you say, if we create a beurocratic system in which the government can precisely monitor the desire of people for certain products and their fullfillment of others, and we can have the state distribute resources from there. Firstly, there is the fact that no beurocracy is efficient enough to do this, as the Soviet Union demonstrates. Its simply impossible to keep up with what people desire and what they no longer desire, and then allocate resources across the nation based on this. The second is that you then have to recognize that you are still cutting into your efficiency, because for the cost of a market mechanism (nothing) you now have a severe economic cost (equipment, wages, labor, etc.) into this complex monitoring system.
My point isn't one on social justice, distribution of wealth or something of that nature. You can settle that and still have the use of a market method through a liberal-socialist or corporatist system. Its that simply put, Marxist-Leninist planned economies can't work because it an inneficient organizational model, not because of human nature. Automotons will still end up with Supermarkets full of Vinegar and nothing else.
