I am amazed that people are criticizing this book because of behaviorism's obsolescence. Maybe Walden Two was presented differently to other people, but I initially read this book as class assignment for Psych 101 at Harvard. Professor Fernald described Skinner's WT as an interesting attempt to apply the principles of behaviorism to a society/community. I doubt even Skinner thought his novel accurately outlined the exact methods by which civilization should operate.
It's not an instruction manual for humanity; it's an exploration of certain models present in most communities. Many of these models still exist in our 21st-century culture. For example, children are still raised to compete with everyone else, through sports and the ubiquitous honor societies. We laud the winners and humiliate the losers. This undoubtedly enhances the inherent duality of the human mind; it exacerbates the (harmful IMO) mode of looking at the world with the "us - them" or "me - everyone else" perspective.
In WT, Skinner presents another way of raising children to allay this competitive, often merciless instinct. Is Skinner's answer the correct solution? One can only assume it isn't, but his solution does make the reader think about these societal patterns that are so often just accepted with no forethought or even conscious choice.
I know people who have/make time in their lives to question the very foundations of our civilization. I let my own life be too hectic; I often just fall into patterns of behavior. However, I do often spend nights reading, and when I randomly pick up Walden Two once every few years, Skinner reminds me that all of the flaws in our society are not absolute rules of human behavior. There other ways to live, and Skinner presents some of his opinions on what those other ways might be.
My own opinion is the Frazier's community in WT is not scalable, not even slightly, but I still greatly enjoy Skinner's exploration of civilization.