DRJAD
I think the overall objective is to make it obvious to the PPL student that flying is not only fun (this often isn't at all obvious during training, when you sweat your way around the circuit!) but that flying "for real", i.e. using modern nav methods, is a good deal easier than one would expect from one's training experience.
On the assumption that every instructor is perfect, a student can achieve this without picking up bad habits, by flying with an instructor. The instructor will probably really enjoy being taken to France and Spain and you name it, or just along the road to Compton Abbas for a beer, but it's going to cost the student an awful lot of money!
Money is the bottom line, and one has to sell any such scheme to the school.