The Onion

It's to do with how the drones operate: A big expensive drone might be fitted with say, a gun or a rocket? The idea being that you fly it out, shoot someone, bring it back and fly it out again.

A suicide drone is much, MUCH cheaper, and consists of a normal drone with a bomb strapped to it. It doesn't come back, it destroys itself in order to give you one cheap drone attack (which is good in areas where your drones are likely to be shot down regardless of if they're a suicide model or not, for example trying to drone strike a densely populated and heavily defended city).