The purpose of the controlled burn is two fold:
1)It reduces the ground debrie that can feed a wild fire, there by reducing the likely hood of wildfires.
2)Pitch pine is extremely tolerant of fire and will regrow after a burn faster than oak and other decidious trees. In fact, there is a variety of pitch pine where the pine cones only open when subjected to intense heat (like fire). This an adaptation for survival resulting from thousands of years of wild fires in the area. Many oak dominated areas of the barrens are the result of no fires (controlled or wild) for a very long time.
So the controlled burn reduces wild fire risks to life and property and at the same time maintains the pine dominant forests that would have existed anyway if humans didn't intervene in fighting wild fires. It is a win win situation, so long as the forest fire service can keep up with such a large area.
Jeff