@Tych Actually, training and upkeep on a human soldier is a lot more expensive than a drone. The military would LOVE if it were viable to replace them all with machines. It has been a LONG time since we just handed people guns and sent them to the front lines.
There are a lot of problems with drones, some of which we don't actually want to fix because we've seen entirely too many Terminator-esque stories to want our real war machines capable of making ANY decisions on their own.
And some of the problems are just embarassing ineptitude. Like computer viruses on unpatched Windows boxes that can't be removed because the removal tools have to go through the same overbuilt bureaucracy that prevents them from installing security patches released over a year ago that would've prevented the infection.
But between those two endpoints are a lot of boring, mundane, practical considerations like "communications can get jammed or decrypted and then we lose our drone, maybe with it coming back at us".
Our story here bypasses that by going the oldschool "hand 'em a gun and ship 'em to the front lines" route, with corruption at all levels making human life incredibly cheap.