Radar guided Hellfires are not well-suited to target individual persons, on foot, in an AO - nor is the Radar for that matter. That is why you have not seen them used a lot in actual combat the last two decades. If the US had been fighting a near-peer, or heck a traditional military force, they would have been more prominent.
It's the same reasoning why pilots don't use A/G Radar much in the GWOT.