|Go away Nostradamus, you are not needed here.|
Those who argue that the Soviet Union failed because it was communism done improperly, and there are a multitude of them, would be wise to heed the warning "Insanity is doing the same thing repeatedly and expecting a different result".
Communism failed, and will fail every time, because human nature does not change. It will fail because power corrupts, not only absolutely but inevitably. Those in power will eventually, inevitably resemble Stalin, Mao or Castro and not Mother Theresa. It will fail because the notion of freedom, of self are inherently anathema to subjugation to a centralized planning authority. It will fail because with a defined outcome, what each individual must input into the system becomes less of a driver for that individual - there is no lasting motivation to put in effort. It will fail because centralized planning is not infallible and one thousand different plans improves the odds of just one (or more) succeeding over only one plan being available/allowed. There are numerous other reasons communism will fail every time it is tried but each of those alone ensure that outcome.