Maybe you’ve seen the talk about iOS multitasking and misconceptions about how it works. I agree it’s not helpful to have Apple Geniuses teaching novice users how to remove apps from the app switcher. But apps do get stuck from time to time, and this can screw up device performance until it’s dealt with. Telling people, “forget it, don’t worry about the multitasking bar” doesn’t help someone who is dealing with a poorly-behaved app.
So what should we tell them instead? As Apple suggests in iOS: Understanding multitasking, before forcing apps to quit, just restart your device.
(Just a hunch, but I bet the folks protesting that there’s no need to manage apps under iOS are extraordinarily picky about the number, type, and quality of apps they run on their devices. They probably run shoddy, problem-prone apps far less often than the folks who show up at Genius Bars frustrated with their iPhones and looking for advice.)