Each CAA exam is 25 questions. The PPL Confuser has about 100 questions for each exam.
IMV anyone who can manage the astonishing feat of memorising the correct letter for each multiple choice answer for each of 100 questions (300 choices in all) deserves an ATPL
And that's assuming they swot up just one exam at a time. Also, the questions aren't exact copies, they are just very similar, so even bringing the book into the exam room would be of little help.
I did actually understand the material but still found the PPC Confuser invaluable as a revision material. Much of the stuff is dross anyway, not relevant to flying.
Ultimately, the problem is the lack of ground school in the PPL. I doubt most schools would want to run it anyway, because there's a lot more money to be made renting out a plane, with an ATPL hour builder instructor, paid say £15/hour, in the RH seat.