score:7
Although the Portuguese had dozens of small forts and watering stations all along the coast at various times, none of these were developed as settlements because South Africa originally had no interesting or valuable trade goods to provide. South Africa has a dry climate and the aborigines were very primitive hunter/gatherers. There were no mines, spices or other useful commodities there, so the colonial nations, including the Portuguese, regarded it as a barren wasteland and more or less ignored it.
Eventually small farmers and ranchers started settling there for the precise reason that it was relatively unoccupied. They could just move in and graze cattle freely. Once this happened, eventually valuable mines and minerals were found in the interior of the country. But originally, none of this was present so the Portuguese had no interest in occupying the land there, especially since there were much larger and developed trading areas such as Mozambique.
Upvote:1
[Portuguese built a small fort in Great Fish River shore1, short-lived: They called the Great Fish River "Rio do Infante", and decided to build a fort there. Short time after, they abandoned it to settle at "Rio de La Goa", unknown location.
Upvote:4
In addition to Tyler Durden's answer, which is right, I would like to note that when crossing from Atlantic to Indian Ocean, ships sail far away from the coast, which is dangerous. Therefore, the area around the Cape Good Hope is not a very good place to build a settlement intended to support the route.
Reference: Parry, J.H. The discovery of the sea. 1974. Doubleday.