@bobotron Wow, thank you, I'm suddenly seeing it a bit more clearly.
I mean most of the Colonial Marines in the movie were assholes, but they weren't all heartless. Many of them were mercenary, and even though they were merc-like, they still patted Newt on the head, or didn't want some kid to get killed.
You can be a mercenary hired to do a job and not go all Apocalypse Now Evil with it. They still took their queues from their officers and the Corporati who set the mission parameters. It's part of the job, and so long as the stories don't push hard limits (like genocidal behavior), the reality would be "Fuck it, put the kids and their daddies on the transport back home. They were stupid for trying to homestead on government property, anyway. Once this job's done I got a barbecue and a beach full of hot people for leave in six weeks, and this cash is gonna buy me a whole lot of tequila."