So many weird old religious rules started out as trying to keep unenlightened but highly religious groups alive, fed, and disease-free, and somehow we've hung onto so much of it. For another example, check out the origin of sacred cows.
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Some of them are intentional from the writers, and some of them are just what people see in it. Cinema is art anyway and just as much of art is about what you take away from it or how you personally interpret things as it is about the artist trying to convey any particular idea or emotion. Art is as deep as the thoughts and emotions it inspires in you.