laughing dog
Contributor
Utterly false. Telling someone to smile is asking them to behave in a certain way. It is literally counterfactual to claim otherwise.Saying "smile" to somebody isn't usually a demand on their behaviour, anymore than saying Goodbye (God be with you) is a demand that they be religious. Saying "Hello" actually usually carries more of a social demand with it, as most people will say "hi" back to it.
Saying Hello or Goodbye to someone is not asking them to do anything. Nor does anyone have to take Goodbye to mean anything other than "Farewell".
Hence your equivalence is baseless.