Cactus
My experience is that some PPLs I have met havent got the faintest clue about what class A or class D airspace means or what it looks like on a half mil chart
That is hard to believe. The airspace is labelled, with clear numbers. Obviously somebody like that will be infringing all the time, but is there any data to support that a significant % of infringers can't actually read the chart? I know a large % of the general public has insufficient literacy for such a task but it should be difficult or impossible for someone that bad to get through the PPL exams (today).
Why don't you take such people to one side and have a "word" with them? Or perhaps have a word with their instructor.
Or report their school to the CAA. I doubt the CAA gives a damn but if enough people reported such schools then something might be done.
This would not happen under FAA - the punter would never get through his oral, never mind the checkride and the preflight planning for the checkride.