Yes, that is very much cultural. You'd probably have the exact same reaction to the average waiter in the US. That "oh my gosh I am just SO GLAD to be here and SERVE YOU and OH MY GOSH this is SO EXCITING" tone is pretty much expected here, even if you're just buying a fucking cup of coffee. US society is full of fake civility, concern and care. "How are you doing" is about the same as "hello" -- nobody gives a shit about how you are actually doing, and the only expected answers are "great" or "well" or "fine". I've come to answer "so far so good", and it's a complete sequence breaker -- people full-on Scooby-Doo at you when you say that. Same with "have a nice day"; I now just answer "I'll try, you too", since I am not omnipotent and do not control such things.