I usually agree with this, usually because we often see things like "icons/logos drawn in pure css", which implies someone maybe thought it was a good idea to actually use in a project.
This demo, however, seems to me to be just for fun. It does serve a purpose though; it's nice to get such an impressive view into what's possible with CSS now, and these demos can also be used for performance testing. It's pretty interesting to take something so rendering-heavy, open a profiler and see what happens when you start transforming, animating, and modifying it (one article comes to mind that uses the "pure css macbook" to demostrate the performance of translate vs. position[1]).
This demo, however, seems to me to be just for fun. It does serve a purpose though; it's nice to get such an impressive view into what's possible with CSS now, and these demos can also be used for performance testing. It's pretty interesting to take something so rendering-heavy, open a profiler and see what happens when you start transforming, animating, and modifying it (one article comes to mind that uses the "pure css macbook" to demostrate the performance of translate vs. position[1]).
[1] http://www.paulirish.com/2012/why-moving-elements-with-trans...