That's funny...
But seriously. I think the folks who don't play something like Nyambe, or Conan, or whatnot DO have a specific, internally consistent view of their world(s). I'll use Robert Jordan's WoT as an example, because I recently reread the first couple books and found a huge FAQ on the net. He uses mixtures of several (real) cultures to form the cultures in his world. Frex, the Aiel are a blend of stuff from the Berbers, Zulu, and a couple of the nomadic Amerind tribes. The Tairens are based on Spain in the time of the Moors; Illian on Renaissance Italy (the city of Illian itself bears a suspicious resemblance to Venice, neh?). Anyone familiar with the world could look at something and say, "No, that doesn't belong" or "Yes, that fits perfectly - I'll use that."
So to answer the question, I reside in the "World Cuisine" camp. We borrowed styles of dress, architecture, etc. to distinguish some of the cultures of our world, which makes it easier for the DM and the others of us who create stuff for the world to make things fit in their proper places, and make everything mesh. Yes, we have monks - the Order of the Black Lotus, the oldest and deadliest assassin's guild in Shtar; we have beholders and dragons and even a tarrasque (the former are bioweapons from the Elder God War, and the tarrasque is a force of the universe, a little-understood creature that cannot truly be slain).
Which camp is "right"? Both of them. Now, for those who play something resembling that travesty in Turanil's post, shame on you. You should sit down and figure out SOME kind of internal consistency - you'll be a lot better off for it.