So it's more of a chicken-and-egg problem than a fundamental JAA-has-silly-requirements one, as I had understood so far?
Because there are so few people who want to obtain a PPL/IR, the education providers do not have PPL/IR courses, only CPL/IR or ATPL/IR. So the PPL/IR people buy the CPL/IR or ATPL/IR courses and decide to obtain their CPL rating in addition to the IR rating because it doesn't cost a lot extra anyway. And because of this the statistics are skewed, leading to the situation that the education providers will not provide PPL/IR training since the market is too small.
(Note: with education providers I mean both the book suppliers like Oxford and Jeppessen, and the FTOs)