FFF,
What you say makes sense. However, while teaching it, why not point out the reasons, and the fact that different types require different treatment, and that different engines are different, and that when flying a new type you should read the POH first and go by that.
As a student, I was never told any of the above. I was told to leave the carb heat on all the way down as it happens. Later on, another instructor said I should push it in on short final. Explanations for both techniques made sense to me. What made less sense was why each egotistical instructor insisted it was done his way, that this was right, and no other way was. What made even less sense, and IMHO is downright dangerous, is that no-one mentioned that it could depend on the aircraft or engine type. I suspect they didn't even know!!!
Students aren't stupid. You can tell them to do something, while pointing out that this may not be the way they should do it now and for evermore, not matter what.
This isn't kindergarten stuff. It's basic, yes, but a lot of it is badly taught at times, and frequently misunderstood. More discussion of it can only be to the good.
