The psychological phenomenon of people being attracted to those who resemble themselves and people they come into contact with most often is thoroughly studied and written about in reputable scholarly journals. The fact that this "professor" immediately dismisses your statement of fact as "naive" only reveals his own intellectual deficiency and lack of objectivity. I bet he was one of those African Studies or Colonialism and Diaspora PhD's. They have no concept of what academic writing is or what an academic is supposed to be. Those types of degrees are just watered down junk history, economics, and sociology. These type of academics get no respect from their peers in other departments and they bitch and moan about no one taking them seriously.