The reason CASA have mandated that circular landing directions should be counter clockwise (CAO 52 appendix 10 para 2.1) is because of the Coriolis effect in the southern hemisphere.
It allows aircraft in the southern hemisphere to always land into the wind, when passing cold fronts and intense low pressure areas would make for a constant tailwind if aircraft were forced to land clockwise on a circular runway.
(NB CAO 52 appendix 10 2.2 then allows ATC to change runway direction temporarily to clockwise in the event of a passing high pressure area if that high pressure area is listed in the current NOTAMs for the specific aerodrome)