Comment by jsdwarf

Strictly speaking, only Austrian grammar school teachers appointed as civil servants were allowed to carry the title Professor. That appointment (Pragmatisierung) is somewhat comparable to academic tenure: you had a job guarantee and the right to stay at "your" school, whereas non-tenured teachers had to switch schools in case of insufficient work hours. But a tenured teacher had a lower salary compared to a non-tenured one and so emperor Franz Josef had the idea with the additional Professor title. A smart move, because he satisfied the academic "vanity" of the teachers which kept salary costs lower.

Since the difference between tenured and non-tenured teachers is beyond the understanding of 10-18 year old pupils, they called every teacher "Professor".