I agree.
Dating back to the old days, when the technology didn't push so far, almost all the knowledge came from teachers.
Teachers were at the top of the knowledge in every fields, and their responsibility was to teach other persons not only just their students, but also people who had this requirements. People learned some skills from teachers, and was able to survive in the society better. This made teachers be respected and appreciated, and because the educational condition was poor, the population of teacher was very small and limited, so teachers were also valued at that time.
Nowadays, when technology grows faster day by day, a large amount of ways to gain knowledge is offered. People can search everything on the Internet or books more conveniently and more effectively, and the door of various knowledge is opened widely. Being a teacher is also noble, but the necessarily of this career is becoming lower and lower that we can't ignore the fact.