That article by Lord Ashcroft mentioned above with the quotes from the various pilots that have landed on St Helena is an eye-opener.
Most telling to me is that his own pilots advised against taking his Falcon 7X to the island. Now I'd have thought that is the sort of aircraft that could have landed on Runway 02, accepting the tailwind penalty, and, in any case could carry plenty of fuel for a diversion back to the mainland if necessary.
I'm assuming here that the turbulence etc on approach to 02 is relatively less than for Runway 20 where the King and Queen rocks blanket the approach from the SE winds. The Comair Director of Ops quoted a "relatively benign" approach from the south I seem to remember in the interview with him.