Do you really need separation of concerns in a 99-line codebase? This is like jQuery all over again. Use the right tool for the job, and consider that the right tool might just be no tool at all.
In a couple year's time, Web Components, Shadow DOM, and Object.observe may very well make application of this size not requiring AngularJS anymore, just like the "no tool at all" document.querySelector replaced jQuery.
I'd be happy to revise the chapter once a suitable polyfill exists for today's browsers — pull requests welcome, too!