The likes of your teacher are scum.
Has Australia changed since the 1980's? I would assume, yes, although I wouldn't bet a large sum on it.
While becoming desensitized to things like that seem to have conferred some degree of personal benefit to you, there are many others to whom people in position of power like your teacher have caused serious harm. I've been under the impression that you were able to stand up to your bullies physically. For others, a teacher being the ringleader of all the bullies may have meant getting physically beaten on a regular basis, money being extorted from them etc. while having no fear of repercussions.
Too much desensitation can have the side effect of distorting one's sense of justice.
Yes, but there has been pushback from what I see in recent years - especially against some groups. politics and news drives this.
Not really. I did get into a couple altercations, but mostly it wasn't physical. I was never a strong kid. There wsas definitely no fear of repercussion at the time though - luckily, I had no money :D
This works on both sides of the equation.