This also explains why when I powered on my iPhone 5 I was greeted with a pop-up message: You will update your iOS NOW or you will update your iOS later. Also explains why when I tried to dismiss the message by pressing the home button I was ignored. I had to power off the phone and delete the update from memory which the phone had already downloaded without my permission and contrary to my setting, Do not update anything.
Apple has all their fanboys lined up around the block to buy the latest shiny toys and to download the latest operating system because it has a larger number e.g. 10.0 vs. 9.3. While I'm a user of Apple products I am no longer a fan.