That said, I'm not sure if I'd be comfortable giving this particular book to a young child. From the sketches it seems as if it will be light on fundamentals like logic and data structures, and a bit heavy on Ruby-specific abstractions and borderline political value judgements. I don't want to tell the younger generation which application stack they should be using, to say nothing of the completely out of place "Apple is selfish, Python is fascist" storyboards.
If you're interested in honest advice I'd remove the parts about what is wrong with all the other technologies and substitute material related to the history and engineering that made all of these tools possible. Mention how strings and floats are encoded as bits, for example. Young children are not going to be wondering why they are learning Ruby instead of C or assembly, but they will be wondering how it does all that cool stuff.