That'd work great if people were earnestly considerate and felt like they were part of a community that they understood whose implicit norms they might consider

That'd work great if people were earnestly considerate and felt like they were part of a community that they understood whose implicit norms they might consider. You don't need bans for stuff like that if people are attentive and thoughtful. People with pets consider other customers in a shop, shopkeepers consider people who are deeply troubled without the support of their pets, and a locally appropriate and nuanced equilibrium shakes out. Unfortunately, we've largely allowed that prerequisite sense of community to erode in many people and many social interactions have become a game of Hungry Hungry Hippos, so formal and rigid policies have to take the place of subjective consideration.