And in terms of effectiveness, consider that you are spending a great deal of money on this unit and therefore hes pretty damn powerful, if he is in the situation were he loses his weapons its your own fault and it would probably make the game a lot more challenging... and the AI very rarely will pick up weapons dropped on the ground (at least in my experience)

The AI seems to pick up weapons sparingly, but it picks them up. The point is, he wants the weapons to die with the actor. If the actor dies and he drops the weapons, if he doesn't make it so they can't be picked up, any trooper can just walk up and take it, eliminating the need to order another trooper that holds the weapon.