this is theory for first time drivers...not everyone is able to judge well...got to have something new drivers to learn from also...even SAF also teaches like that...
I'd strongly advocate to not cling to cookie-cutter instructions, but use your own judgement. You can't really learn to ride a bicycle either by reading, you have to do it.
If you are really good at parallel parking with a 3/4 turn of the steering wheel, but the manual says you should do a full turn, what would you do? And do you think all cars have the same steering characteristics?
I notice that in this thread, a lot of attention is paid to small technicalities, e.g. how to release the clutch, when exactly to shift gears, etc. I would argue it's infinitely more important to focus on road safety. Stalling the engine is mildly embarassing and may hurt your ego, but an accident may result in physical harm.
Here's a true story (although admittedy I may not remember all the details accurately) that happened a few years ago in Germany. In poor visibility, a BMW driver relied on the instructions of his fancy GPS navigation system, which told him to turn. The car ended up in a river, as the GPS didn't tell him that after turning, he had to wait for the ferry to arrive.
If the driving centres really emphasize blindly following standard operating procedures, they are IMHO in need of a big whack with the clue stick.