Cabin in the Woods has been getting massive amounts of hype. As The Guardian pointed out, it is credited as "a total game-changer," "mind-blowing" and "the start of something new." That's a heavy burden for any film to carry and I'm not even sure that this one lives up to that.
Don't get me wrong, it's a good, maybe even very good movie. But is it mind-blowing? Not really. Is it going to completely redefine the horror genre? I doubt it. The first Scream movie came out in 1996 and yes it was a fresh take on the horror genre but it didn't mean that all horror movies became meta-commentaries on horror movies. If that were the case, it would have become kind of hard, redundant and pointless to comment on a genre that was simply reflective commentary.
Scream didn't redefine horror tropes nor did it fundamentally shape the future of horror films as a whole. And the same is true of Cabin. Sure, it's nice to see some smart people look at a genre they love critically and cleverly, but it's probably not going to amount to much more than that.
As The Guardian's David Cox says,
If this supposedly mind-blowing exercise isn't actually frightening, wherein might lie its supposed transcendence? Clearly the high concept must hold the answer, and indeed producer and co-writer Joss Whedon has kindly tipped us a wink. The Cabin in the Woods, he tells us, is not just "a joyous scary movie" but also "a critique of the horror film."
So what exactly does it take to change a genre? Tropes become tropes for a reason and once they're set they become difficult to change, often being sent up as fodder by more intelligent entries like Cabin and Scream.
Remember when all first person shooters were set in World War II? After Call of Duty 4: Modern Warfare that completely changed and now modern, urban, un-named-istan warfare has become its own trope. What made the first Modern Warfare game so successful and game-changing was not that it was commenting on the genre itself but that it was a completely new and fresh interpretation of the same core concept. It wasn't that CoD4 was suddenly a hyper-intellectual breakdown of the first person shooter, but rather that it was just a new, better first person shooter. Its what games get (most often from the indie space) and what movies seem to lack so often. They may change slightly in terms of style and execution, but it's much harder to redefine the tropes that make up a genre.