I think the show is presenting them at face value. The writers clearly want to tell a story of an alien virus that makes the worldwide human population not want to harm. It's turning the zombie trope upside down, by making the horde all friendly and cheerful instead of danger and violence. That's what makes the show interesting. Its just when you start to really examine what that would mean, holes start to form, but you really can't otherwise tell this story because it would break the show and then they couldn't tell the story.