Exactly and this is why things are not always as easy as it looks like.
Cave diving is for most of us a hobby, and don't do what you don't like. And do what you like as safe as possible.
And about teaching, from what I read about this restriction, it is not a thing that will ever be teached in a course. So maybe it was too early for the divers, but if you can move a little bit foreward, there is also a risk that moving backwards is impossible. So getting out of a serious restriction can be really hard then.
I try to get some narrower spots also in a course and sometimes I go to a really small cave that is not worth diving outside of a course. But it starts very wide and then gets smaller and smaller in just a few minutes swimming. There is no risk of getting stucked, turning is always possible as it is only narrow in heigth, not in width. I tell them, you can swim in as far as you feel well. There is no right or wrong, but go till you think this is enough. You see some divers turn really early. Not wrong, they just learned what their limits were.
But about responsible instructing, when I was looking for a ccr cave crossover, I contacted an instructor who said that to pass that crossover I had to dive my backmount rebreather in the Truffe cave. I said, I have tried it, but where a twin12 fits, the Inspiration for sure does not fit. He said that I had to take my unit in front of me and then squeeze in and then put the unit back on my back. I haven't done that crossover with this instructor. I have never teached a ccr cave class in this cave, in my eyes this is equipment removal for sure. I am not afraid of diving in caves, but I will never squeeze myself into a restriction when I have to remove my ccr from my back. Then I have sidemount equipment if needed.