That's exactly why Lion is more beginner friendly. They don't need to know how to quit an app anymore. Why would you ever care to quit an app? That's a legacy concept that's so ingrained in the author's memory that he can't comprehend not knowing it. Think, instead, of all the time his parents wasted trying to understand this quitting apps thing.

My girlfriend was using my iPhone and kept asking me "how do I quit the browser now." She was used to a PocketPC/WM phone, where if you don't manage your open apps, your phone crawls. I had to keep saying: "don't worry about it, just lock the phone. There is no closing."

10 years from now we will look back on quitting apps and saving files as relics of the ancient times, like floppy disks and parallel ports.