I don’t know why Apple hasn’t yet explicitly told all retail employees that “killing apps” in the multitasking tray is unnecessary, unlikely to solve any problem, and actually unlikely to have any effect at all due to the way iOS multitasks.
It’s one thing to hear this myth from the idiots at AT&T and Verizon stores, but it’s just embarrassing for Apple’s own retail employees to be peddling placebos that imply that iOS can’t multitask without constant babysitting and manual maintenance.
I don’t spend a lot of time in Apple retail stores. And I know some people who work at them, so I mean no offense. From what people who work there have told me, it’s not the greatest place to work. As a result, I am not necessarily sure that they hire the top echelon people either. I can tell you that the few conversations I had with them over the last couple of years (as well as the conversations I have overheard) have led me to believe they don’t know as much as they should.
On the other hand, these employees might just be trying to cut corners and appease customers.