like I said in the video, I admit it is not a replacement technique of SVG for icons, but it does have its niche use cases. When I prototype, or I need some simple icon that I want to animate when hover, CSS is easier. You can see a lot of hamburger icon out there are done by css. This is a reference so that someone else don't need to redraw the hambuger icon in css again and again.

Beyond that I have positioned it as an CSS learning tool. I spent more time making the web app than doing the icons, with angular.js, so that one can click on any icon and inspect and learn these css tricks within 10 mins or so. The easiest way to learn any programming language is to do a hands-on project, and I find cssicon is bite-sized project that give the learner some learning satisfaction within the ideal short time span. I hope this helps someone