What on earth is the appeal of "rocket stoves?"

If you go to YouTube and type in "Rocket Stove" you be overwhelmed by the number of entries. These are little homemade wood stoves made out of bricks or metal which burn hot and fast. They are nothing which any six year old couldn't have made in 20 minutes on a Saturday morning. Yet the builders are so proud of their projects that they post videos of the things before they've even finished the first one, let alone made one that works better than lighting a pile of sticks on the sidewalk. Man!