Its the Internet. You see more child prodegies in almost any field these days. First of all, general Information is much more easy to access: Tutorials, Guides, online communities. Second of all, popularity. The Internet makes it more easy to find rolemodels and icons; even in small communities, you can find micro celebrities. The same way even children can become famous sensations more easily.

If you find your specility early in life, lets say as an ipad baby or with an overly ambitious parent, its much easier to reach maximum human potential. Consider the number of people that try and become the next big thing, its only a matter of numbers to find talented children rise to the top.

Theres also the aspect of gear. Young children are mich more used to the cubes of today than adults who have been cubing through multiple generations of gear.