I suppose, but given the balance between 'something to protect' and 'vulnerability' the fact that people don't walk around in obviously dangerous places with their guns out might show why not doing so in a more safe place doesn't occur. To answer your question more directly though, because there's nothing unsafe about people at my front door, and that's also why the restaurant down the street lets people walk in without question. Wouldn't want to live where conditions are otherwise, sympathetic to those who do.