It was almost as if she was...

What annoyed me was how the main characters can't walk or drive without crashing or impaling themselves on something. It happens way too many times in this movie, to the point where I thought it crossed into lazy writing.

But for your other point, wouldn't it kill the genre if everybody started doing conceal carry? The movies would be all setup and no payoff. That thrill killing psychopath isn't so scary anymore with a bunch of bullets in his head. I actually think it could have worked for this movie, though. Let's say that Fassbender had pulled a Glock and started blasting punks, say, at the campfire scene as they're attacking after trying to run him down. The movie sets itself up in the early scenes as a conflict between classes, but it never really pays off. They could have moved in that direction and shown the aftermath of the shootings and how it would play out with the characters and their families in the police investigation, media and courtrooms. That would have made for a more original movie if not a better one.

I was trying to think of a horror movie set in the real world where the victim doesn't behave like a panicking, clueless idiot. All I've got is No Country for Old Men. Almost always its liberal, white, bobo, city people in over their heads out in the woods or inside the old mansion.