This is a good idea but it's certainly not new. It's commonly called "constructionism" and was put forward by Seymour Papert back in the 60's or 70's. Based on the work of Jean Piaget, constructionism basically holds that you learn by building or constructing something, particularly if you do it in public view. This is why Papert created Logo. He wasn't just looking for a new way to play with his massive Lego collection; he had a sound theoretical framework for learning and cognition and was looking for a way to try it out.

This seems like a good study but it has one major flaw. The authors are generalizing the results of the study to the entire population, "youth." However they used a qualitative research approach which does not allow for generalization. Moreover, there is insufficient description of who actually participated in the study and how these people were recruited for the study to allow readers to make their own generalizations. I think the results of the study are good, the authors just need to be more careful about drawing sweeping inferences from them.