Here is a response to the question that I have not seen in the thread, though it may be as wrong as any other postulation.
When landing on a Helicopter Carrier (as in LPH/LHA) the aircraft approaches from the port (left) side on a 45 degree angle. The PIC has the best view of the deck and superstructure.
Although I think the translating tendancy is the real reason, the above was proposed in a discussion of this subject in the 80s.
