Recently an editor rejected a query (she didn't see the story, just the idea) because I was proposing to write a story about someone very different from myself.
What kind of an editorial policy is that for fiction? A man can't write a woman? An atheist can't write a Christian? An young person can't write an old person? An earthling can't write an alien? We'll be killing off all genre fiction then, I suppose.
On this topic, friend protested that he agreed with the editor, that the best literature came out of writing about one's own experiences. He cited Dostoyevsky. Hey, I love Dostoyevsky, but I also love Shakespeare, and I'm pretty sure he wasn't always writing about himself.