Going with the premise that the roots of fantasy are attempts at Neo-mythological storytelling, I'd like to point out that all mythologies were, in at least some capacity, reflective of the times in which they first emerged. Greek mythology largely reflects Ancient Greece's societies and values, as embodied in the various literature of its playwrights, epic poets, and religious storytellers. Roman mythology that occurred later reflected more the values of Roman society. If you read The Epic of Gilgamesh, or even various religious and mythological texts from the ancient Fertile Crescent, you'll notice that those stories also reflect their own society. Further, many of these stories were revised as their societies evolved. The heroic aspects of Enkidu are different from the heroic aspects of Heracles or Jason, which are different from the heroic aspects of biblical heroes like David or Samson.
Even Tolkien's work largely reflected the values of his own religion, society, and culture. English culture and Catholic faith permeate the themes of his works. The Forgotten Realms were first realized between the years of 1967-1987, and have continued to this day. Insofar as they are works of neo-mythological storytelling with collaborative components, they may have initially represented a world of the mid-20th century and its values. But the world has changed. And, like all mythology, so too has the characteristics and ways in which it reflects our society. If you want to go back to mid-20th century mythology, you can, but the storytelling of today is inspired by the world in which we live, its values, its social structure, and its dreams of escape into another world.
