Why are most aliens bilaterally symmetric bipeds?
Most films are set in environments where humans and aliens can interact, so considerations are made about gravity, speech etc. The most outrageous life forms on our planet live in such different conditions that they just would not work in a film. If you see what I mean. It is all ultimately about good guys and bad guys fighting. Beings that are able to fight and communicate – and even have relate able facial expressions, bleed and die, show emotion are just essential to story telling. I am not intending to rubbish your point of view because it is a very good one, but telling the story in a way that engages the audience is more important than creating aliens as bizarre and exotic as the creatures that inhabit the seas of our own planet. We have to be able to relate to the aliens, and amorphous blobs just don’t do it.
