A while back, I asked if libertarian political theory was an ex post rationalization used simply to justify the cause of freedom without actually explaining why it worked. It seems reasonable to ask a similar question of socialism: is socialist political theory* simply a rationalization for pursuing a certain course of action?
At first blush, the answer is no. Socialist theory is pretty robust and generally accepted as sound. For example, one tenet of socialism is the redistribution of wealth, wherein it is theorized that poverty can be eliminated by taking money from rich people and giving it to those classified as poor. This proposition is so self-evidently true that it borders on being tautological.
Yet, every time the redistribution of wealth is put into practice, it generally tends to not eliminate poverty. Of course, poverty can never be eliminated if it is defined in relative terms. But, even when poverty is defined absolutely, there are still some who persist in living in poverty, and no government program is apparently able to change that fact.
Thus, it is to be concluded that socialism is nothing more than an ex ante rationalization. How else to explain its unmitigated and predictable failure? Incidentally, the reason why socialism continues to fail in practice is simply due to the fact that the theory is predicated on artificial class constructions, and can therefore never truly and properly account for individual motivation. It should be note, though, that libertarian political theory accounts for individual motivation but is still incapable of explaining why humans do what they do.
At any rate, the easily observed fact of the matter is that socialist political theory has little grasp of reality, and continues to fail miserably. It only use is in convincing people that there is a reason to try collectivism in spite of its miserable and repetitive failures.
* Please note that “socialist political theory” is a broad term that covers any political movement that generally tends toward increasing government power instead of limiting it. This stands in contrast to libertarian political theory, which refers to any political movement that attempts to limit government power instead of increasing it.