The problem is that the two options here doesn't fully grasp the situation. Let's say you're the leader of a poor country, and a lot of your country doesn't have access to water. You don't have constriction equipment to make the water supply yourself, but you have SOME money. A private company comes and offers to supply the water to everyone, but they're going to charge for it to cover their cost and make some money. Now everyone has water but it's a private commodity. To complicate things "clean" drinking water, like we have in the rich world. Is really hard and expensive to make.

You also suffer from a "tragedy of the commons" if you just make water free for everyone all the time. At some point you have to charge for it, or I could just use it for all the stupid stuff I want, or a big company could use it to turn a generator then send it back so it's much more expensive. The advantage to privatizing it is that a company will control the price so that they can make improvements and upgrades to the system, a public system will need money from outside the supply to maintain itself.

I've made the case for the private commodity here, there are MANY problems with it.