You are missing my point, in all of the examples that you used you referred to technologies that were really unknown to people, or had never been privatised anywhere in the world before successfully. There I agree with you, government involvement could make sense. 

However, I am specifically referring to technological issues that have already been privatised in more sophisticated economies than our own. Why do we have to go through these highly inefficient stages if the technology has already been sufficiently developed and mastered to serve our current needs? 

As an example, not to long ago we did not manufacture any cars in South Africa. When we did, Government did not start up its own car manufacturing operation. Or are there some South African brand cars that I am unaware of?

The same goes for desalination and management of the water supply. The international private market knows how to do it and make a buck off it. As long as government keeps a watchful eye it will be fine.