Cannery Row is a place on the map, but it's also a community of lovely people: the "whores, pimps, gamblers, and sons of bitches" that Steinbeck talks about in the beginning (0.1). It may be a rough place, but you can find tons of examples of people in Cannery Row helping each other out and generally being big softies. In fact, it seems like the folks in Cannery Row are as dependent upon each other as these girls. Cannery Row? Try Cannery Pyramid. When there's a flu epidemic, they all pull together. And when Mack and the boys are miserable, everybody else is too.
Even though Doc is important to the community of Cannery Row, he's not really a part of it.
Doc is the most important member of the community of Cannery Row. Everyone is indebted to him and everyone loves him.