I completely agree with the instructor's expectation that students act responsibly and arrive prepared, and that there be consequences if they don't. From that point forward, however, I must disagree with his actions and his statements.
First of all, he's correct (IMO) to treat students as adults and to expect adult-like behavior from them; but he has to be realistic in his expectations, as well as the consequences he administers. Some students are going to fall short some of the time. Unless he's a brand new teacher, he knows that and should be better prepared to address it with a minimum of class interruption. Pompous drama is unnecessary, disrupting and unproductive.
Students aren't all motivated by, nor do they all respond to, the same stimuli. Public embarassment and dismissal undoubtedly worked to straighten up some of the students he castigated, at least temporarily; but I'll bet it simply made others decide, if they have the option, to drop his class or at least resolve never to take another class from him.
It's his job as a teacher to try to motivate and direct students in different ways, to reach as many of those who paid to receive his services as he can. I
never favor coddling students or compromising achievement standards; but I also know--as do most experienced supervisors and teachers --that in the long run, public praise works only some of the time and public reprimand, particularly if it includes ridicule, virtually never works. If he'd taken the time to meet with the offending students outside class to discuss/convey the consequences of their lack of preparedness, preferably privately and separately, I think he could have been far more effective--assuming his goal is to teach, rather than to preach.
And I agree with him that an aptitude for music is a gift, a great gift that is accompanied by a responsibility. But that responsibility extends to ourselves, to those who gave us or loaned us money to attend his classes and, perhaps, to our families and friends. It's not a responsibility to change the world. Whether he likes it or not, each of us is responsible for cultural improvement and that includes everyone: doctors, lawyers, homemakers, clergymen, carpenters, mechanics, etc.--even politicians, not just artists. It's a responsibility that arises from being a human being and a member of society, not from selecting a particular occupation or avocation. It was self-righteous and inappropriate for him to pontificate to your class and suggest that he had some divine insight into the salvation of mankind.
I do appreciate your sharing it, though. It confirms my belief that I was right to avoid some of the self-important, stuffed shirt professors that I managed to avoid when I was a music theory major.
Good luck to you.
Bluesy Soul