Not really? Improv is a thing outside of RPGs. Round-robin writing projects are the closest metaphor to role-playing I can think of, where control of the story passes through many hands and no one person can know what will happen.
The GM doesn't know what the players are going to do (and being surprised by what your players come up with is part of the fun of being a GM), but they probably do have a general idea of where they want the story to go, and probably some subplots planned to go along with specific characters. Having one of your protagonists drop dead because of a single bad Fort save is going to disrupt that a lot more than anything your players are likely to do.
I don't think it's a coincidence that D&D, the game where it's easy to die arbitrarily, is also the game that makes it easy to bring people back from the dead.
If the players are being suicidal or colossal dicks, then by all means, there should be consequences for that behavior. But that's not usually what happens in D&D. Usually it's more like "saw a bodak, rolled one bad roll, dropped dead." (Lost 4/5th of a party that way, once.)
Nobody in any of my gaming groups is a gambling addict who wants to bet it all on one roll of the dice.
Different players have different things they like best about an RPG--following the story, making unique characters, doing cool stuff, coming up with outside the box ideas--but I don't think I've ever played with anyone who found being at the whim of the RNG to be the fun part.
You're probably right. I hadn't heard anything one way or another, so I wasn't sure what the official rule was.
Actually, there are quite a few non-core Pathfinder classes that strike me as being particularly well-suited for a horror-themed setting like Ravenloft. Inquisitor is all about that gothic monster-hunting, and provides a divine-themed skill-monkey class. Medium and some of the other occult classes seem particularly suited for gothic horror. Vigilante is all about hiding your true identity, even hiding your alignment and preventing scrying, so someone could seem harmless to the evil overlords but be secretly a hero.