A lot of ESL people talk about the difference between Training Centres and Public Schools like there is some important differences in quality or 'the type of people' or as you suggested there is some elite 'real teachers' in public schools compared to the lesser trash in Training Centers.

I've done both and still do both today. Sometimes running from a University class 'across the road' to a private Training Center and its not some big meaningful difference in terms of teachers, staff, quality, quanitity, lesson planning or anything other than one point you made..

..its true often public school kids (and this goes up to University levels too) but they have to be there and may not want to be there at all. They may or may not care whatsoever about Oral English classes. They may well talk on their phones or be obnoxious or sometimes just entirely bored and sleep through it.

To the other side of things: the Training Centres young adult or adult classes yes will more likely be full of students who've paid their own cash and/or very much want to be there. So now Paul pay attention to this part:

Because of this I need to be more skilled, better, sharper, more attentive, a 'higher quality teacher' than I was in the public classroom. Where a dog could drone on reading and pointing at pages and get away with it because in fact the kids don't have parents outside who dropped 5400 on classes from their pockets and the kids could care less anyways.

So.. again to your point: Yes, you (if anything) need to be a better teacher in a training centre IF anything. (I like to think everyone gives every class the best they have no matter what anyways).

Those working in public schools are usually pretty good. They are the same who teach in Training centers. The difference is very often overrated by what I guess is people who got a job at a public school then want to pretend they've 'leveled up' in some pathetic need for that.