Teaching it as a standard manoeuvre is wrong. The stats prove this ...
I'd be very surprised if that were the case, and invite you to cite these "stats". While it may be possible to find statistics that demonstrate that the success of the turnback as an untaught manoeuvre is low, the turnback has not been systematically included in the PPL syllabus for a very long time. Thus I don't think you can claim anything about the merits or otherwise of teaching it on the basis of statistics.