I've taught people in areas a lot more dangerous than cave diving. I've been a student in many different activities; some pretty simple and some fairly dangerous.
But, common to all is that the instructor who thinks of himself/herself as a fence to be hurdled, or a "hardass" in anything more advanced than basic training is missing the boat entirely. So is the student who is not willing to work and put full effort into learning; or who considers any particular kind of diving something to satisfy his/her machismo.
It is entirely proper to insist that a student learn the skills necessary to keep themselves alive. The old saying is that sweat spilled in training replaces blood spilled in reality. That is not only an old saying it true; for some literally and for others symbolically.
Teaching is best done by motivating, encouraging and helping the student succeed. With one caveat; the student has to be willing and working. There is no room for a student who will not work, or who is not willing.
I have, without hesitation or compunction washed out students who would not work, or who were not willing. There are a few who just could not master the tasks. For those I reluctantly, but necessarily, washed them out. But, for the willing workers washouts are few and far between.
There are students who, in my opinion, have a distorted view of recreational scuba diving. These folks look as "tech training" as something akin to special forces or pseudo-seal training. These folks apparently eat up the kind of training mentioned in this thread. They would be much better served by a dose of reality that our kind of diving is Fun Diving and not some machismo excercise.
So if you are a student: be willing to work your butt off. Expect an instructor who will work with you and encourage you; and will brag about how you were such a clutz before training but now have a clue. Anything else is definitely off key.