Tony thats my issue really. The standards are too low. Too many Instructors interested only in the hours in there log book and not interested in what should really be the bulk of the PPL which is how to find the answers to this stuff.
The average PPL students lose a lot of flying time to bad weather, that should be used for ground school covering the sort of stuff that is not in the PPL exams.
I think things like the confuser make it even worse as it encourages students just to study for the exams rather than using the exams as a test for a broader knowledge base.
Stepping down from my high horse now....