Part of that is the cultural status of teachers. But another large contributor is the policy status of teachers w.r.t rate of pay, autonomy, and educational requirements.
All teachers must obtain a Masters. They are paid in line with expected median or greater for those of their educational level. They are also, by policy, the main driving force and final say on curriculums and educational program design. Further, they are expected to remain current within their field and often publish throughout their career.
In other words, the pay and job preference is the type that attracts the academically minded. And does so without requiring them to assume standards of living far below their educational investment.
Society at large lends respect to fields based, by and large, on superficial reasons. In the U.S. we offer teachers pay and respect (within the job) more in line with short order cooks with a G.E.D. than professionals. Society's treatment of the profession reflects that.