Well that's a relief then - we can ignore the decline in the quality of white players produced by SA and blame it on those dasterdly non-whites. The fact that they haven't come close to replacing Donald, Kirsten, Cullinan &, in effect, Pollock who's only a shadow of his former self? Apparently irrelevant. Likewise the fact that fixtures like Gibbs & Ntini are worth their place whatever their skin colour. Likewise the fact that there' s been plenty of moderate whites over the last few years as well as the non-whites of a similar standard.
Even to an outside like me, it's obvious that the summary dismissal of most of the non-whites earlier in this thread was simplistic. Personally, I was delighted that Langveldt was ignored for Dale Steyn at the start of England's last tour, especially after CL had skittled us in the previous week's warm-up. Sure enough, the SA attack couldn't hit a barn door and we won the 1st test at a canter. AFAICS Prince & Amla are not obviously lesser players than Dippenaar, Rudolph, Van Jaarsfeld or McKenzie. Take away their boot-filling exercises against Bang and/or Zim, they're all moderate. Ngam actually did really well in is handful of games until injuries kicked in. Zondeki was probably a bit lucky to be picked in 2003, but he gutsed it out with the bat to set up a famous win at Headingly, so he didn't exactly let anybody down. I'll grant you Tsolekile and Ontong, but how many games did they play anyway?
Pratyush was spot on. They haven't found adequate replacements for their best players in the 1990's / early 2000's. Even more importantly, whereas Cronje's side dug in and exceeded the sum of their parts, this lot tend to do slightly the opposite (although they're not too special anyway). And from where I'm sat, the captain doesn't help a lot either.
There's maybe an interesting discussion to be had about why they overachieved in the 1990's. I reckon that starting with a generation who spent much of their careers missing out through SA's isolation probably did alot for team spirit ("NOW we'll show them ..."), and obviously that can't be replicated. But the fact that Cronje was a smarter captain probably had more to do with it.