React Isomorphic Demo
It is possible to use React without relying completely on client-side JavaScript to render all your content—though it’s certainly not the default way most tutorials teach React. This ongoing tutorial aims to redress that imbalance.
Besides the main benefit of server rendering giving faster page loads, it also enables large amounts of the site to run without JavaScript. There are many reasons why you would want this, but my personal reasons are that it allows you to completely drop support JavaScript in older browsers, but still have the site function.