Benjamin Clayborne
Auror
I don't really buy into the whole "writing what you're familiar with" aspect of all fantasy being medieval Europe.
What people are familiar with is (as you point out) a nonsensical caricature of medieval European culture. "Familiar with" and "accurately informed about" are not the same thing. Most Westerners expect fantasy to look like the fantasy they've seen before, and the fantasy they've seen before is Fake Medieval European. So when people read and write it, they expect and create Fake Medieval European.