As to why so many of the rightist thugs in our day, both with and without executive power, both the Mussolini wannabes of the DJT type and their acolytes, have clothed themselves and their movements in religious garb, it may be useful to consider two voices, and two visions, not from this century but from the nineteenth. It is a matter of where Marx was wrong and where Dostoevsky, at his most pessimistic and in spite of himself, was right.
The failure of Marxism—not as analysis of conditions in Marx's time and place, not as assessment of political economy generally, but its failure as future vision—is essentially a matter of the revolutionary subject, or its absence. The proletariat may have been united in a revolutionary vision here and there—a factory, a city, a region, even a whole industry. But that unity rarely if ever took hold on a national level, let alone a continental or global one.
The Grand Inquisitor embodies an unpleasant vision, and one hostile to Dostoevsky's own thinking, but not without considerable truth to it. If miracle, mystery, and authority are not all that inspire humans, still they are often decisive, as against economic class interest, in questions of whom to follow, what movement or movements to join. Miracle and mystery—or mystification, to be precise—are religious matters almost by definition. As for authority, a leader's claim that his or hers is sanctioned by that of God or gods is all too likely to trump any authority warranted by fact, majority rule, or constitutional law. What is the appeal of Dostoevsky's unholy triad? Perhaps it is this: People too often think they sense peace, or at least its shadow, in surcease of thought.
I agree in substance with you. However I think the "failure of Marxism" as a "future vision" is inherent in any "future vision" that espouses a goal. Society is collective and collaborative and while ideas and their movements have sway over its development, expecting them to effect persistent, directed and goal driven outcomes ignores the dynamic nature of social development. As societies are made up of individuals, albeit with emergent properties, their movements (and the goals of movements) are necessarily segmented generationally and evolve in response to evolving conditions. Marxism, or dialectic materialsim, in espousing a goal driven "future vision", looses sight of the dynamic and undirected nature of historical dialectics.
Just my ideas and analysis - I can't offer any sources.