BOAC:
The concept of a 'back course' without a 'front course' is one I will pass on.
A bit like having a backing group with no 'star' up front or a back-up power supply with no primary
Your points would be well taken if the installation were for an approach procedure. But, this is a special case to provide correct sensing for missed approach and departure procedures. When this was installed, RNAV was a limited concept (pre-GPS) so there was no other way to get the course guidance needed to avoid the higher terrain to the southwest of the airport.