The essentials of the cloud computing controversy are two competing impulses: saving time/money/effort, and fear/caution.
The argument for cloud computing, boiled down, says roughly, "Why go to the trouble of choosing, buying, installing, connecting, maintaining, and fixing computers and networks when you can just hire it done by experts? You don't grow your own food/build your own car/teach your own children, do you? Just get rid of all the hassle, and let us do it all for a modest monthly fee".
The argument against says, "If your apps and data are important to you, why would you surrender control of them to someone you don't even know, using unspecified equipment and staff in an unspecified place? The only thing you do know about them is that their only reason for being in this business is to make stacks of money - which means they have to charge you more than their services are worth".
IMHO there is no adequate analogy that casts any useful light on the cloud decision. (And I'm a great one for analogies usually). Gas and electricity are completely different, because they are undifferentiated commodities. Even phone service just provides pipes to talk down and switches to choose whom you talk to. Computers can do pretty well anything you can think of, as long as it can be rigorously specified through algorithms. It's a very big leap of faith to say that you are prepared to trust some complete stranger, motivated purely by the profit motive, with something as potentially vital as that.
If you have a few hours to spare, like thrillers, and have an open mind then I advise reading Michael Connelly's "The Scarecrow" to get some idea of what the worst case could be. Sure, it's sensational - but I couldn't find anything impossible, or even implausible, in his scenario.