[I also think "demo classes" are useless and a total waste of time.

You are right, SB. Not only demo lessons are a total waste of time, but also effort. The assessment can be unfair or biased towards the teacher giving the demo lesson if he or she is evaluated by those who are NOT experienced, qualified or certified school teachers. A teacher giving a demo lesson can also be disadvantaged if he or she is giving the lesson not in a natural setting, that is, ‘the atmosphere is not there’ as in a real class.

A training school, or any school for that matter, can get rid of an outspoken teacher by finding faults with his or her teaching. The slightest fault is enough to send the teacher out of the school.

The students can easily know whether a teacher is a good teacher or not. You cannot fool them. Can we still remember the teachers who taught us in our school-days? How many of them had left a lasting impression on us?