Hank Williams makes an excellent point about the restriction that apps on the iPhone may not run in the background.
[the] issue [of resource limiting applications] has been dealt with in Unix, and with real time systems for many years.
In short, this argument is a strategically placed fig leaf, which is easily blown away.
Previously, I thought the no background applications restriction was a good call on Apple’s part. This article totally changed my mind. Williams is right; and Apple will have to lift this restriction before long, or risk being overtaken Android and others.