yes it is important thing but it should be not the first and most important thing in keeping the family together
director of the movie is putting "instict" or "low desire" on the top of importnace in marriage..
why do u always think that we have to be "perfect in the bedroom " even after 50 ... ??
there can be diffrent factor what can change everything (kids, stress, poverty,war,illness) and than what
whole movie can finish "in the garbage"
partnership and marriege is something more that the sex
whatever you will do it will become boring and change with the time
its why we build our relation on something more important
love, famiily, friendship, torah and good deeds are tools for happy marriege and life