I think that everybody 'has a feeling in their water' a 'gut reaction' which tells the sensible that, communism of virtually any type or hue, is doomed to fail.But why so? - Primarily, any attempt to 'deify Man' or to replace the Creator has not started too well when the sinful nature of Man is replaced with a silly belief in 'the inherent goodness of Man'. You start by flying in the face of reality and attempting to darwinise Man as somebody tending to evolve into 'something better, nobler and of a higher order' is simply laughable.
In practical terms you just cannot pay a surgeon the same as a roadsweeper. If you do, you have disincentivised your society.
BUT if you do pay a different level then your society has removed the non-elitist, 'we are all in this together' base which was your starting point. What you now have is a society with different levels - perhaps we should call them classes!
(All this assumes of course, that greed and selfishness had been entirely absent from day one anyway.)
