The aerial drones are not immediately near ground troops. A little RC truck would never be very far from them. Therefore, by picking up video signals from the cheap recon device, combatants could know where the ground troops are going to be very soon and from what direction they're coming.
Furthermore, picking up the source of the RC controller would mean combatants could tell exactly where the troops are. In the case of an aerial drone, piloting happens from an air conditioned trailer, often across the globe. So that's less of an issue.
Furthermore, picking up the source of the RC controller would mean combatants could tell exactly where the troops are. In the case of an aerial drone, piloting happens from an air conditioned trailer, often across the globe. So that's less of an issue.