There's a difference between ambiguity that's integrated into a story and ambiguity that's forced on the viewer. If the only thing that makes the movie ambiguous is that the final shot of the film isn't five minutes longer, then that is the type of film I hate. All Is Lost, The Grey, Save Yourselves, etc. If it's woven into the story from the beginning then I have no issue with it even if it may not be for me.