Yeah, I should have phrased that differently actually. Open endings can be great and very powerful, depending on the narrative/events so far. A lot of films that are primarily about exposing a problematic situation in society should probably actually end open-ended (at least to some extent), rather than having the sort of cathartic ending where everything comes together (or ends in ruin) for the story's protagnists - causes that suggests the situation is now over (for better or worse), while in everyday reality nothing has actually changed.
And for the Coen films, thinking of it more, the person actually said this in a way that suggested that the Coen's are just
that deep/smart - cause my response was something like 'well, I'm not stupid, have seens lots of films, have really tried very hard to get it, and I don't - so I'm declaring these a lost cause'.
Of course, emotional state also come into it. If the film is trying to evoke a feeling/emotion rather than a specific point, and that feeling/emotion really doesn't resonate with you at that point in time, then it's not gonna do anything for you.
Pity.
(I generally like them actually, probably just except those films, and mostly because I felt deceived at the end.)