It is an interesting read, although it is a pity he chose Zebra Cabs to be representative of metered taxis. Zebra cabs is good by metered taxi standards as far as I know - far better than the average.
His point about regulated charges is a good one though. If what he says is true, then Zebra cabs is unable to compete on price. What the government should do is do away with prescribed rates altogether and let the market sort it out. Yes, Uber cabs should be regulated as far as safety and the RAF goes, but not price. It makes no sense to regulate the price.
Also interesting - Uber Black is R14 more expensive for faster and better service. UberX would be cheaper and faster than Zebra.