First, a white-tower point: if you look at the client and server as a whole, doing any kind of dynamic view generation on the server is a complete violation of MVC. You shouldn't tell the view how to view.

That said, server-side rendering is a product of historical inertia. Remember, client-side MVC is the way things were quite successfully done before the internets came along. However, browsers originally sucked at anything "client", so we developed languages and design patterns and libraries that slowly made the concept of a server-generated view tolerable, to the point where many sites (e.g. HN or Wikipedia) are actually better served by doing everything on the server. Now that javascript is powerful enough though (and we can cross-compile from languages better suited to complex application development), client-side MVC is unsurprisingly making a comeback.