I think we're saying the same thing, really. When you say that people can't always manage to look cheerful, but they should at least greet the person warmly... That, really, is all I'm saying. (I am English, remember! Our "warm friendliness" would probably seem like cold reserve to you Americans... And I'm not entirely joking, having read my "Watching the English.") I never expect staff to look at me as if I'm the highlight of their day - I'd feel patronised if they did - but I don't want rudeness, or a total lack of human interaction, which is what I too-often get.

Over here we think of the approach that comes up with a huge smile, and an "Hi, can I help you!" and a "Have a nice day!" as being "American." (A lot of things get called "American" - often disapprovingly - and probably with no justification at all.) I don't even go into shops when someone is lurking at the door to greet me, and I get pounced on by falsely-smiling people, asking if they can help me. I think staff should be adept at reading body language, and go and offer help to those people who are clearly a bit lost and in need of it, but leave well alone those who obviously are doing fine by themselves.