There's a good essay on Marxism in Tolkiens universe that tries to understand it's near-universal appeal. It basically comes down to nostalgia for an idealized feudal past without forced labor, poverty, famines or plagues. There's even a section on this in the manifesto :

Owing to their historical position, it became the vocation of the aristocracies of France and England to write pamphlets against modern bourgeois society....In order to arouse sympathy, the aristocracy was obliged to lose sight, apparently, of its own interests, and to formulate their indictment against the bourgeoisie in the interest of the exploited working class alone. Thus, the aristocracy took their revenge by singing lampoons on their new masters and whispering in his ears sinister prophesies of coming catastrophe. In this way arose feudal Socialism: half lamentation, half lampoon; half an echo of the past, half menace of the future; at times, by its bitter, witty and incisive criticism, striking the bourgeoisie to the very heart’s core; but always ludicrous in its effect, through total incapacity to comprehend the march of modern history....