The airplane conversations of mental health professionals vs. sociologists

According to this New York Times article, people who work in mental health professions are much more likely to hear about the personal lives of their seatmates:

Pity the traveling mental health professional. While many travelers find strangers reveal information they might not in other contexts, psychologists, psychiatrists and social workers say they must negotiate a range of interpersonal, ethical and legal issues as they travel.

So while these professionals look for ways to not reveal too much about their jobs so they are not inundated with the personal lives of others, one professional suggests saying that he is a sociologist takes care of the issue:

Niranjan S. Karnik, a psychiatrist and sociologist who teaches at the University of Chicago, said he often told seatmates, “ ‘I’m a sociologist.’ That’s an effective conversation-ender.”

I would like to hear more about this. Is this because the seatmate doesn’t know what a sociologist is or does? Or is it because people perceive it to be a boring or uninteresting profession?