Marxists often can't stand it that the rest of us don't see the rightness and appeal behind their ideas, but I've simply never known a committed Marxist who didn't also seem like a self-righteous misanthrope. This hardly makes Marxism appealing except, perhaps, to other self-righteous misanthropes who identify with the aggressor. Idealizations aren't, after all, necessarily about identification with all-good objects. For some, only the destructive power of aggression can be idealized.
Theodore Dalrymple compares Marxism and radical Islam in an interesting discussion of Sayyid Qutb’s book, Milestones (There Is No God but Politics). He argues (correctly, I believe) that fundamentalism is essentially the defensive of precarious beliefs. Though Dalrymple doesn't say so, Marxist hyper-intellectualism often looks like the manic but brittle defense of a precarious underlying sense of self that the believer tries to shore up by relentlessly constructing an ever more towering house of cards in pursuit of some elusive sense of omnipotent perfection.
The experience-distant intellectualism common to so many Marxists strikes me as an intellectual sophisticate's version of defensive religious fundamentalism; it is closed to challenging data and deployed in fierce attacks on skeptics who cannot help but notice the unmooring of belief and logical systems from any reasonable claim of evidence or experience.
Psychoanalyst Heinz Kohut and others since him (and our clinical experience, as well) have convincingly shown us that idealizations serve an important self-maintenance function; they appear to provide a sense of internal cohesion through fantasy fusion with the perfection of the idealized object. The idealized object is omnipotent and viable, therefore we are viable through an affirming fusion of power and purpose found in our tie to the idealized object.
In healthier persons, a strong element of realism evolves, tempering idealizations, thereby allowing for the acknowledgment and even appreciation for humanizing faults and flaws in the idealized person or humanly constructed belief system. This tempering allows for a more resilient maintenance of higher values and purpose in the face of limiting imperfections.
In contrast to the calmer reactions seen when tempered, mature idealizations are challenged, if you poke at a more precarious idealization, you will frequently witness disintegration into narcissistic rage. In those whose idealizations are brittle and untempered by realism, there is no give, no resilience, when challenged. This is a plainly observable phenomenon, both clinically and in everyday life.
This is why I believe that Marxism, Islamic fundamentalism and other religious fundamentalist movements are inherently prone to degeneration into authoritarian regimes supported by murderous aggression. Their adherents cannot bear challenges that expose the imperfections of their brittle, precarious idealizations. The regular occurrence of scapegoating 'purges' that seem endemic and essential to the preservation of these belief systems only serve to underscore their function as stabilizing ties to fantasied perfection. To maintain the stabilizing function of a defensive idealization, impurity must be repeatedly rendered and destroyed or the sense of perfection found in the tie to the perfect object will be lost.
H/T: Andrew Sullivan