Since there is a lot of code added to support this, why do we even bother handling it ?
The client-side routing seemed pretty fine to me so I don't understand.
The beginning of the lesson 13-server-rendering should start by explaining why we would want to do it in a real situation.
It's not a React Router issue, and your best bet is to look at SlideShare for "universal rendering" or "isomorphic rendering". The short answer: speed, SEO, and testability.
Since there is a lot of code added to support this, why do we even bother handling it ? The client-side routing seemed pretty fine to me so I don't understand. The beginning of the lesson
13-server-rendering
should start by explaining why we would want to do it in a real situation.