It's cultural, yes, but this particular example isn't necessarily emblematic. In American english, "How are you?" isn't a literal question, it's a conventional greeting. The answer is expected to be "Not bad" or "Fine" or "Well" -- not because of a desire to sugarcoat everything, but simply because it functions linguistically as a start-of-conversation marker or just a standalone greeting. People are thrown off when someone responds immediately with an honest, in-depth answer about how their life is. It's like pinging a server and getting back a process list. Unfortunately it happens to be that our implementation of certain conversation protocols is slightly different in mutually confusing ways :) <-- sugarcoating

Most languages have their own version of adjacent question/answer pairs that don't really function as literal questions. Searching for "have you eaten yet?" will pull up lots of interesting examples.