Any field or roadside may be a convenient place to relieve one's self but it is hardly a functioning toilet, not more than the grass in front of your house. In other words, not in my front yard. But your idea of sanitation may be different. After all, humans and farm animals have sometimes shared the same dwelling.
Thoreau said, in so many words, that the poor are not so much hungry, naked or cold so much as they are dirty, ragged and gross. The poster child of naturism in this thread is just about all of those things, although it's not possible to determine if he's hungry. If it's San Francisco, however, he's unlikely to be hot.
I have seen actual homeless people, not referring to the panhandlers that presently occupy choice corner locations way out here in the suburbs, but those living in little cardboard, plywood and canvas shanties off in the woods not far from the highway--until they're shooed away into another jurisdiction. I have sometimes wondered if urban renewal and slum neighborhood destruction create at least some homelessness. If nothing else, they likely make a neighborhood too expensive for the poor to live in, which may or may not be an object, and also creates a sterile neighborhood with none of the street level businesses, such as they were, that existed before. Ultimately, it appears that the goal is merely to push the poor out of the way and out of sight and incidentally, further away from wherever they might have been employed.