Communism Fails in Theory Too

I occasionally see the phrase "communism works in theory too" or some variant.  It is usually used to express skepticism about an idea without actually giving a reason for that skepticism. 

The phrase always bothers me a little bit because communism doesn't just fail in practice but also in theory.  And I am not even talking about theory of "man's nature" where communism supposedly works if men are perfect but fails because we somehow fall short of its ideal.

Communism fails, even in theory, because it centralizes control over resources.  In reality, information is subjective, time-sensitive, and distributed among everyone.  Only a system that allows individuals to act on the basis of the information they possess can succeed, both morally and economically.  Communism denies that ability for the individual to act and places the burden on a centralized authority.

This failure of communism is especially relevant with respect to money.  The pricing structure in a free-market economy emerges from the actions of all individuals who participate in the economy.  This structure is the primary information used by individuals to guide how they allocate scarce resources.  In "pure" communism, there is no money and therefore no means for the central authority to meaningfully determine how to allocate scarce resources. 

Even "on paper", communism can only result in mass destruction, starvation, and authoritarianism.