I disagree. Sometimes, you just can't fathom how hard it is to be someone else. Stephen King's Carrie had no personality, just a hunger to live a normal life (based off the movie, at least). The Shining, though? Some of his best work, because he could make a framework of his life and some of the difficulties he went through and transpose them to a character of similar gender/race. They say put a few monkeys in a room with a typewriter and they could write Shakespeare, but could they write Mandela's story? Or Pursuit of Happiness? I don't know, but those stories are made more powerful because the author lived it. You can have general knowledge of a particular subject, but completely lose its magic and mystery when you haven't lived it; those people get accused of "phoning it in". Its better to say nothing at all than to say anything about something you know little about personally only to incur the wrath of people who have dealt with it.
Yes, a (good/great) writer would do the research to find out more, live in similar conditions, etc. But would a heterosexual man write a more compelling book on LGBT issues than a person of that community? Does a caucasian male from Manhatten know how to write 'Hood Books' better than someone who has lived in the 'hood'? Anything is possible, but leaving it to someone better suited to it isn't wrong. Maybe a little cowardly, but not inherently wrong.