I don’t think this is a bad tutorial at all, yes it doesn’t give you the full code, but not all tutorials are meant to do so. And I think the new react-router is not easy to grasp at first (I’m still trying to fully understand it).
The way the tutorial goes through each piece of the puzzle is much better than the official documentation.
That all said I know it must be hard for a beginner to understand all the concepts, my advice is for you to try to create your own tutorial, and here I’m not being sarcastic, it is an honest advice. I find it very useful when I’m learning something to try to explain it to someone else, it always help me fully grasp the understanding I require.