I have to disagree that the act of telling someone "Smile!" is rude or chauvinistic or any of the other labels ascribed to it. The follow up shirtiness, not to mention the odious use of sweetie or baby coupled with the request, is what I would consider rude or entitled. Chauvinism and patriarchal motivations are best assessed on a case by case basis.
Now, I am a smiler. Almost chronically. I like to smile at people and, generally - even if they don't smile back - I get an acknowledgement back. Sometimes, though, I get a steaming plate of sourpuss grumpy face. I don't say anything but the urge to be even more cheerful in light of the po face is a bit hard to overcome. Would my relentlessly cheery smile be similarly construed as a verbal command to smile?