Oh I fully understand, it's just that I was brought up with good manners and feel it is only right to give my attention to the person serving me.
But that has nothing to do with the cashier's need to pay attention to the customer, which is something they are paid to do. A cashier doesn't pay attention to a customer because they have good manners, they do it because that is their job. The equivalency you suggest does not exist.
Gov Kodos wrote:
They're employed to provide a service, they're not serfs to be taken for granted.
This is hyperbole, taking a phonecall while you are also chucking things in a bag is not treating someone like a serf or taking them for granted, it is letting them do their job while you get on with what you want to do.