The first “world” setting for Dungeons & Dragons was Gary Gygax’s campaign world, the World of Greyhawk (though Tekumel was published in a very similar game as Empire of the Petal Throne first, and Blackmoor was the first small setting it should be noted). Though the players of Gygax’s game often did not take it very seriously – and their characters who have become canon reflect this – it’s quite clear from the writing in the early Gazetteer of the world, and his essays in First Edition AD&D, that Gygax himself took the world fairly seriously. Greyhawk is a world with a sweeping, epic history, but one grounded in realistic tribal migrations and interactions of states. Magic events of huge proportions shape the past and present, but the world that they leave behind makes a certain sense in their wake.
Does nostalgia play a part in wanting to revisit the World of Greyhawk? Certainly, and even moreso, there is a sense that playing the world with D&D never did it justice. It would seem that the system promoted a style of play that even ticked Gygax off, when his players failed to take the game seriously. We can solve this problem by creating a system that will allow the players to explore the setting in earnest, and leave the silly clichés at the door.