To me yes, when the film is not just about the mystery, like Pablo Hernado’s Berserker (2015).
From Conan Doyle, Agatha Christie to more contemporary crime fictions such as True Detective, Stieg Larsson’s Millennium series, Gone Girl, etc… the world loves mystery. I love mystery. We all love solving a puzzle. As a story goes we will gather hints and reconstruct the events ourselves. That is a truly fun part in reading a mystery fiction. It does not matter whether you solve the case yourselves or the writer present the killer(s) to you on the table, ultimately, for any mystery story, the readers/audience need to know who, how and why.
Strangely, out of mere coincidence, I have run into a series of open-ended mystery fictions this month. Pablo Hernado's Berserker is one of them. When the movie finished and the end credits rolled up, the girl sitting beside me leapt forward, with both her palms raised to shoulder height, even in the darkness I could see her mouth wide open and her face expressing a big “WHAT?”.
*Article contains spoilers