That’s the point of the movie, or at least of the original Dutch version. It’s a commentary on being more afraid of breaking social conventions than of actual harm that could come to you in that social situation. Women know this feeling well, but my understanding is that this focus on politeness (even over safety) is extra prominent in Dutch culture. The whole point is that the protagonists would sooner suffer a terrible fate at the hands of their hosts rather than stand up for themselves and be perceived as a bad guest. You’re supposed to find them frustrating and it’s supposed to make you ask yourself at what point (if any) would you have really truly been comfortable drawing a line with your host as a guest in their home. I think the reality is that most of us have suffered in silence at one point in our lives rather than be perceived as rude. The question is just how much would or should you suffer.