You don't propose alternatives to rail esp to move large numbers - Uber? Really. And SAA is a bad example - it's NOT a "mass" public transport system, even by international standards, but a luxury, niche item few working people can afford, the antithesis of "public". In fact, there's numerous airlines that are profitable. Currently, SAA is a wasteful trophy for the ANC government to boast about. A transport engineering professor I knew was angry about Gautrain - nationally, billions spent to benefit a small region; why not fix rail - intercity and nationally - and rapid bus systems? If SA had a decent public rail system eg Europeans and Japan (US is NOT a good example bec they neglected rail, and their road infrastructure is deteriorating), we may be persuaded to leave expensive motor vehicles and use train (and rapid bus) for local and long distance. 
Public transport is one of the best examples of a public good that has broad benefit but not intended to make profit, don't you know?