Noel Malcolm makes a good point at Standpoint:

...[T]he arch-practitioners of infantilification are to be found in two walks of life: nurses, and air hostesses. Both use the same sing-song voice, and the same universal verb, to “pop”. “I’ll just pop the thermometer in your mouth”, says the nurse; “I’ll just pop your bag in the overhead locker”, says the hostess. The verb comes from the nursery, and its purpose is to put us back there.

On recent flights I have noticed a further refinement: a simple instruction, such as “Could you put up the window-blind, please”, has now become “Could you put up the window-blind for me?” The implication is not that she was about to do it herself, but that she wants you to do it just for her sake, to show how much you desire to please her; the underlying model for this sentence is, therefore, “Could you put your toys away for me?”

Why is this all so grating? The simple and obvious reason is that I am not an infant, and she is not my mother, aunt or nanny; there is a falseness about it which is silly and instantly tiresome. But to falseness one must also add hypocrisy: a way of talking to us that is meant to seem warm and personal is, in reality, nothing more than a managerial technique, and nothing could be less warm than that. And, finally, there is the element of sheer insult: do they really think we would not cooperate if they just asked us politely, speaking as one adult to another?