When you've been playing D&D since the mid-80s, you see a lot of published campaign worlds come and go. Some, like Greyhawk, Dragonlance, and the Forgotten Realms, become icons of the game. Others, like the Judge's Guild Wilderlands, Arduin, and Kingdoms of Kalamar, fill solid niches, even if they never reach the same level of popularity. And a great many disappear altogether from the published world, kept alive only by shadowy cults who worship in the dark corners of the internet.
Ahem. Sorry, romanticizing a bit here.
In the 90s, TSR engaged in a number of grand attempts to create unique, non-European worlds for fun and profit. Two in particular stand out in my mind: Darksun and Taladas (the lost continent of Krynn). Taladas has a very special place in my heart, in no small part because the authors clearly had a great love for culture, and spent a great many pages detailing what the lives of people who lived on a continent that still bled a sea of lava at its center were like. They also took great joy in subverting, spindling, and mutilating every cliche we had grown comfortable with in Dragonlance: Kender weren't just ADHD and annoying, they were paranoid and stole your stuff to keep you from using it against them. The most civilized nation on the continent was an early-Roman pastache ruled by minotaurs. Many of the elves were plainsmen in the north. Etc. I'll have to do a retrospective one of these days.
So why wasn't Taladas a commercial success? I could blame the lack of support (e.g., novels, modules, advertising), but there's a deeper issue at work: Too much fantastic (yes, I'm using that as a noun) all at once is like too much spice in your food.
D&D works because it taps into the Western collective unconcious, combining the familiar elements of myth and fairy tale with our self-perception that we are natural explorers. A good D&D setting has its own familiar tropes which make it easy for anyone who has played the game, or who has simply been exposed to a bit of fantasy to drop right in and feel at home. Changing a few assumptions around--say, making your elves exiles from the woods who now live on the plains, as Katherine Kerr has done in her Deverry cycle--is like adding a pinch of spice to that old standby meal of beef stew. But changing too much at once makes it more difficult for a person to digest what you're setting before them.
Veteran players, temporarily bored with faux-English countryside and woodland elves, may find delight in such settings, but in the long run, we all return to the comfortable and familiar.
It's better to start the PCs off in an area where they can make an instant connection and then introduce new elements as they range father about than to require them to read three single-spaced pages just to get an idea what their native culture is supposed to be like. They want to kill things and take their stuff, not take a course in anthropology.