Although this is difficult to quantify, I believe this explosion has most likely helped the design industry. Many designers have become a lot more famous than they would have before being on TV. Moreover, many amateur designers have been able to participate in these shows and thus develop their career, contributing to the industry. Finally, many people have felt inspired by these shows and hired designers to redecorate their houses, which has also been positive for the industry.
Wouldn't it be rhythm, the use of recurring elements to direct the movement of the viewer's eye's through the product of art and give a sense of unity to the composition. correct me if im wrong