There's a recurring analogy of Cloud as utility, such as electrical power. I'm not convinced by this, and regard a comparison of the Cloud with the restaurant trade as more interesting. Read on...
Few IT departments build their own hardware, in the same way that few people grow their own food or keep their own livestock. Most buy from a supplier, in the same way that most buy food from a supermarket.
You could avoid cooking by eating out for every meal. Food as a Service, in current IT parlance.
The Cloud shares other properties with a restaurant. It operates on demand. It's self service, in the sense that anyone can walk in and order - you don't have to be a chef. There's a fixed menu of dishes, and portion sizes are fixed. It deals with wide fluctuations of usage throughout the day. For basic dishes, it can be more expensive than cooking at home. It's elastic, and scales, whereas most people would struggle if 100 visitors suddenly dropped by for dinner.
There's a wide choice of restaurants. And a wide variety of pricing models to match - Prix Fixe, a la carte, all you can eat.
Based on this analogy, the current infatuation with moving everything to the cloud would be the same as telling everybody that they shouldn't cook at home, but should always order in or eat out. You no longer need a kitchen, white goods, or utensils, nor do you need to retain any culinary skills.
Sure, some people do eat primarily at a basic burger bar. Some eat out all the time. Some have abandoned the kitchen. Is it appropriate for everyone?
Many people go out to eat not necessarily to avoid preparing their own food, but to eat dishes they cannot prepare at home, to try something new, or for special occasions.
In other words, while you can eat out for every meal, Food as a Service really comes into its own when it delivers capabilities beyond that of your own kitchen. Whether that be in the expertise of its staff, the tools in its kitchens, or the special ingredients that it can source, a restaurant can take your tastebuds places that your own kitchen can't.
As for the lunacy that is Private Cloud, that's really like setting up your own industrial kitchen and hiring your own chefs to run it.