This thread will just be filled with anti-government people who will spout their theory without data and without ever considering anything anyone else says. It is the sad truth about those types of people.
In most cases, governmental control is inefficient. Thus, it should be avoided in most cases. You don't want government control of stores, most industry, etc. But that doesn't mean it is bad in all cases.
Also, we aren't talking government control vs. a competetive market. It is government control vs a monopoly/duopoly. Thus, we don't get the benefits of true competition. We are comparing inefficient government to inefficient monopoly.
When it comes to utilites, generally the bigger the cheaper. Building an entire water treatment plant for a town of 300 is a huge waste; instead combine that town with other nearby towns and build just one plant.
If the choice is many private monopolies vs one large government utility, it'll be far more efficient and far cheaper to have the large government controlled utility. If the choice is many local utilities vs one large private monopoly, I'd choose the large monopoly any day.
The worst situation of all though, is to routinely switch from regulation to deregulation. Each time there is a switch (either way) the customers suffer.