If the clutch held in method is now taught by instructors surely this is plain wrong. This lazy mechanically unsympathetic method can quickly develop into the even lazier hill hold without handbrake whereby you see cars rocking back and forwards, wearing clutch plates and thrust bearing.
Our youngest got her driver's license 6 years ago and also had to learn this nonsense. I think two things have come together: firstly, everything is subordinated to the environment, so no unnecessary gas or noise. On the other hand, modern engine management maintains the idling frequency in a way that was not possible in the past. In other words, you can start modern manual cars with this soulless method on the hill but not a single car that is 20 years old.