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".

Small correction: only grammar school teachers are called Professors in Austria, junior high school teachers just "Herr/Frau LehrerIn". In earlier days, you needed a master degree to teach in grammar school and just a bachelor degree for junior high.

*every school teacher after secondary school. Before that they're still mostly "Mr./Mrs. Teacher".

> Every school teacher is a Professor.

Same in Poland! But only for high school.