It does seem, looking here and elsewhere, and out of the transparent bits of the cockpit, that airmanship is on a downward trend.
Fortunately, in the less crowded airspace of the north we have not yet been too inconvenienced by it. I do recall, though, some situations where I have apparently not been seen by another pilot: situations both within and without the circuit.
I had the good fortune to be taught by a variety of instructors, all of whom encouraged me to think about what is going on. Situational awareness has so far, and I am touching wood as I type, not eluded me.
I believe, however, that the important point is that students be encouraged to think for themselves, from the first moment of setting foot on the airfield prior to flight. I fear that formulaic teaching breeds formulaic pilots - who believe that if they do everything in the cockpit that they learnt, then they will be safe, no matter what else is going on around them. In other words, their safety is entirely the result of the observation and good reactions of others, and they are failing to reciprocate to the benefit of all.