I think it boils down to the whole "we learn by doing" thing that's at the heart of a lot of play. And especially for kids, imitating what you see the adults in your life do all the time holds some mystique and new-ness that makes boring tasks seem like exciting activities. To us, filing taxes and loading the washing machine are repetitive tasks we do out of necessity, but to kids, it's a "grown-up thing" to be able to do.