It absolutely takes a controlling personality to dare to presume that people around you need to smile to satisfy the idea of a greater good based on social aesthetics. You can't just decide how others should feel.

Smiling isn't some trivial task like recycling where you can tell people to 'just do it because it's good for the environment'. People have their own lives going on. With their own trauma, grief, and hardships that you may not understand. They could be emotionally exhausted from barely keeping it together instead of mentally breaking down in public.