Are Cultural Outsiders Our Writers of Choice?

The Rutgers-based child_lit listserv is revisiting the question of authenticity, discussing once again who has the right to write about whom. One quote from a contributor (thanks, Ebony) jumped out at me:
We are biased in favor of stories that make us comfortable ... and that means that we are more likely to praise a book written by someone with our background and voice ABOUT a different culture, rather than a book written BY someone inside that culture with a different, but more authentic, voice. This is the way that insider voices get "silenced" -- they don't get published as often, or purchased as often, or talked about as often ... because we're a dramatically homogeneous group of people in this industry.
I'm not sure if I agree, but I want to hear what others think. Is there a demand for children's or teen books set in other countries but penned by westerners because the western reader (wallet in hand) resonates with that outside-looking-in perspective? With all the talk about "authenticity" going around the world of children's literature, is there still a need for a book about a particular place or culture written by an outsider for other outsiders?