I hate to be negative, but what really is the point of this? That a simple webpage without any content can be fast? Of course it can. Is it desirable to inline your CSS, "like a boss?" Maybe if you have one single web page. What if you have dynamic content and your users intend to browse more than one page? With externalized CSS, that is all cached. Same with images. If I'm building a web application, I certainly do…
The main driving point is probably the fact that there is sometimes no need to build pages that rely on all manner of JavaScript etc.