I will think a bit more about the essay quote; it deserves some reflection before comment.
Briefly, at present, I will say that TLotR is morally fortifying, but not at all because it's pedantic in character or a morality tale in genre. I'd say that it is fortifying because of the quality and authenticity of its "sub-creation." On this issue, Tolkien's poem Mythopoeia comes to mind for me.