In my experience, this stems from a difference in comfort level between students and professors. Professors often begin class on the first day by inviting peopl

In my experience, this stems from a difference in comfort level between students and professors. Professors often begin class on the first day by inviting people to call them by their first name. Students, however, are normally intimidated and still call them Dr. whatever. Thus, the professor wants to be on a first name basis with the class, but the feeling is not reciprocated.