At the end of the 19th century it seemed clear to many that free market capitalism would not work: that it was unsustainable; and that in order to make it work, the entire social system would break down in the attempts to paper over capitalist production's contradictions. They came up with both socialism and fascism as alternatives, and those alternatives elicited a long ideological war that wracked the world for the ensuing century.
Because the alternatives were wrong, however, did not make capitalism right. Those contradictions of capitalism were and still are operating. The late 19th century diagnoses of the problem are still sound. It's just that we've been judging the accuracy of the diagnosis of the illness on the basis of the effectiveness of the cure, and the world alas still hasn't found a cure for advanced metastatic capitalism.
In some subtle way, the common sense intuition is correct: to judge the soundness of the diagnosis by the effectiveness of the cure has a deep logic to it. It must be the case that diagnoses which fail to cure are missing something crucial.
Our conjecture is that the alternatives all mistakenly depend on the workings of government. Our own theory has it that the cure for capitalism could be found in the biblical regime; that a society and a political/economy that was purely secular could not work because a healthy social political economic organization requires sacred institutions to make them work right; and that the location of the sacred institutions needed (1) to temper the power of the rulers, and (2) to support the values of the root of the society's legitimacy, of every society's legitimacy: its civil society.