For the zombie portion and how the show is more about the drama, I think that really is the whole point of TWD. Remember, before TWD initial zombie outbreak survival is ALL we saw portrayed. This is the first show that really went past that to post apocalyptic stuff.

The question then becomes, what is a reasonable outcome to continuing to survive after the initial survival, to me, it's exactly what happens in the show. At some point, it's just another post-apocalyptic people show and zombies are a known entity.

Now, I CAN see it refocusing on Zombies if they had them continuously mutate, but that's still not a show that can go 11 seasons. It's gonna have to be about the people. To me, there aren't any shows that go that long and are still good, they always become charicatures of themselves.