Originally Posted by
Cheetah_SA
Maybe, as was the case when the UK introduced visas for Saffers, the noose was tightened because corruption in the Department of Home Affairs made ZA passports untrustworthy.

But those passports were phased out and the new ones have a much higher standard, in fact I find them to often be of higher quality in terms of the bio page than most other country's passports I've seen, save for the lack of biometric information encoded in a chip in them.
I heard rumours last year the UK was going to re-introduce visa-free travel in the coming years as all the phased out passports would be expiring around about now.