The difficulty is that anything more complex is TOO complex as an example. This is meant to demonstrate the MVC of a thing. With this example, I can quickly examine the structure and feel of a given tool, an hold the entire example in my head. When you start stacking all of the other bits on too, this starts to become more difficult. What TodoMVC allows is a quick survey to narrow down contenders. At that point I can examine the other crucial aspects and understand if they work for my project.