There are obvious difficulties with this in a welfare society - what, for example, motivates anyone to produce under this scheme? In order to provide a motivation for production that credo is changed to "from each according to his ability to each according to his contribution." "...in its first steps the workers’ state cannot yet permit everyone to work "according to his abilities" – that is, as much as he can and wishes to – nor can it reward everyone "according to his needs", regardless of the work he does." (Leon Trotsky, The Revolution Betrayed, Ch 3). This is a situation that must be adhered to while mankind is being perfected, during a "lower" state of communism.
That had a couple of interesting effects - it appealed to the scriptural "he who does not work, neither shall he eat," it had precedents within the labor movement before the Russian revolution, and it provided grounds for the justification of greater rewards for Party faithfuls, the "brainworkers," whose contribution in presumably advancing the cause of socialism was placed at a premium over that of producing tractors or food.
Stalin took it one step further in his Constitution, replacing "contribution" with "work." At this point the State has expropriated wealth and distributes it according to its view of the value of one's productive efforts first in maintaining the State and then in advancing the cause of international revolution. It is, in effect, a return to autocracy, as Milovan Djilas pointed out in The New Class, a volume that did not endear him to the nomenklatura then or now. Trotsky attempted to couch the advent of this new bureaucratic group not as a class, but as a "caste," a splitting of hairs unusually fine for even him.
It's all about the maintenance of control and the distribution of largesse, and the emergence of this sort of ruling class is what Rand is presenting in progress at the time of Atlas Shrugged. The people in Washington D.C. so dedicated to the suppression of Reardon metal (more on this in the next chapter) are so strictly as a function of their ability to control its applications, reap the rewards, and distribute those to other ruling class members. Reardon's, Dagny's, and the others' sin is that they are outside this putative ruling class and do not intend to join it. And, in fact, are morally incapable of doing so.