It would probably be the loiter. Sure you can order in something and it gets dropped. Then the fighter returns to base. The A-10 affords flexibility to those units that are doing counterinsurgency against people that will attack, retreat, attack, retreat, attack. So you can probably use the A-10 repeatedly as you track down where the "enemy" is.

Plus, maybe you didn't get the first sighting correct, or once the JDAM hits a bunch of others scurry and you want more.