I think Bourdain did mention that the middle class, both black and white, left the city when he was listing the many reasons for the city's problems and I agree it's not his job to explain everything. That being said, it brings up a good point. Most outsiders don't realize that it wasn't the white people leaving that pushed the city into bankruptcy. That happened a long time ago. It was when 200,000 black middle class packed up and left that pushed the city over the edge.