You have to remember that we, as an audience, have a larger perception of danger by knowing the genre. The mind's ability to think can be altered by all kinds of things, such as adrenaline and panic. Horror movies do often rely on bad decisions, but so many bad decisions happen in reality without consequences because we're not in a horror story.

There's also the sheer number of horror stories out there, which highlights the poor decisions as tropey and the more aware of a trick, the less effective it becomes. That's where subversive movies like Cabin in the Woods get material from.

I don't think directors are doing it on purpose, but rather they're too attached to their story to realize it. They get deep into each character's reasoning and that can make a trope appear original or acceptable. The audience doesn't spend years bringing the story to life, so they just see more stupid choices. It's a blindspot for the creators.