I don't think wicket is that easy to be honest - Amla & Elgar must have played well. Also, I am sure Kohli and his bowler suffered from "Typical Indian Test wicket syndrome", which is on under prepared wickets, after day 3, you just need to keep it tight on one spot, wicket will do rest against batsmen not skilled enough to counter vicious turning ball. It'll never happen in J'burg - you have to bend back and you have to keep batsman surprising and you'll have to make them ply with new ball. J'burg is one place where, one can leave lot on length.
Regarding the wicket, I think they kept excessive grass than normal. Usual J'burg track is hard, with lots of clay (89%! some times), BUT not much grass. That makes the hard and fast, but not much lateral movement. Normally, Day 1 is a bit slower, day 2 the fastest, 3 in best for batting (if you can play on back foot), Day 4 as well, but it starts to crack. Day 5 can go either way, but normally hit the deck type pacers find some cracks on business areas.
Here, I think for too much grass, it moved too much in early innings, but bounce saved batsmen (otherwise, you could have seen 3rd innings starting by lunch on Day 2). 2nd day wicket got harder and that grass made it uneven - but it can be awkward for bowlers as well, because they can't focus on a target (unless batsmen are chickened out).
By Day 3 & 4 I think grass has dried a bit, moisture of top surface has evaporated and that heavy roller some what bonded the top surface. It'll explode later, but by that time match should be finished either way. Had the target been 300+, I can bet SAF won't have used the heavy roller - that would have brought the 2nd ball with 50+ needed and cracks opening with grass; 7/8 wickets at hand might not be sufficient then.
