Kids like dirt

Awhile back we got rid of our old play set, bought a new one and moved it to the other side of the yard.  So we were left with a big mulched area that I used for my garden earlier this spring.  Now we want to clean up, seed and turn it all into grass (moving my garden next spring to a spot with a little more sun).....anywho, that work should be done later this week but in the meantime the kids have had a field day 'gardening' and throwing dirt at each other.  Yesterday they (along with their neighbor friends) played outside for a good 2-3 hours....making rolly-polly farms, erecting a shrine to the good ole USA (obviously) and general good dirt fun.   Remind me again why we're getting rid of this?