I greatly admire your opinion here but you need to take into context as to why SA are being able to do this type of batting.
1) This is the kind of pitch we see in the UAE, slow DEAD tracks with little bounce and little spin. In such tracks rear guard is relatively easy and with spinners bowling, who are used to turners, would not necessarily know how to exploit such a track.
SA were given this track because of the hue and cry that was made at the Nagpur pitch earlier. Had this been a turner like the previous one this type of Innings in the Sub Continent on turners especially is, mark my words, A DISASTER.
They would feel good about it in the short run as to what they might have achieved but this kind of success would make such an innings a benchmark. Young SA batsman watching such a show would make of the notion that in order to survive on 'Indian Turners' you need a dead bat approach which is totally opposite to the dynamics of how batters play on Sub Continent turners.
Give this same pitch to a line up consisting of Hafeez, Azhar, YK, Misbah, Asad & Sarfaraz with the same set of spinners operating and these blokes will show you how to chase down this given total.
I don't see the logic in such an approach especially when you're 3-0 down in the series. Eng in 2013 gave India a phainta of epic proportions in India by doing totally opposite of what the South Africans are doing right now. YOU need to understand, on Turners, dead bat approach is counter productive.