People don’t want to go off grid.
People want to supplement the grid.
Only if it makes financial sense to do so. If people can't make some money out of selling back to the grid then they're not going to invest in doing so. Tshwane's 10c/kWh is a big fat, middle finger towards solar producers.
If I was able to sell back to the grid at a reasonable tariff I would consider doing it as part of a passive income retirement plan. It's never going to happen in South Africa because who will then subsidise the non-paying residents as well as line the pockets of municipal officials.