A bland expression isn't respectful, it's bland. Apart from the really fake stuff, which I agree is goofy and just as much an expression of weakness, I also think to some a smile is "goofy" because they can't possibly imagine having good reason to smile even as an intelligent, responsible person. That might make sense in Russia, for gangsta rap, African child soldiers, and so on -- in scenarios where the average person doesn't have the resources and the firm grounding to be open towards the unknown and the stranger, where kindness can only be some kind of plea for mercy or patronizing, instead of the simple friendliness of someone at peace with themselves and their surroundings.

Maybe I'll stop smiling briefly when I pass by someone who will just misunderstand it; but when I'm with myself and the world, or with people or animals who are content, I smile a lot. Why not? Not doing so would be the mental equivalent of not just smoking, but lighting cigarettes with hundred dollar bills.