|Credit to artist at DeviantArt|
One could hardly imagine how a phallic symbol artwork by H.R. Giger spawned a design that would inspire fear in people.
However, it's hard to miss the apparent xenophobia that these movies. It applies not only to aliens but to robots. Ludditism/technophobia and xenophobia had become a significant part of American society, and it contributes to the anti-intellectualism that became the source of one of Isaac Asimov's more famous sayings. Perhaps Hollywood should cut down on alien invasion themes and perhaps have a story where the opposite happens - human invasion of an alien world. And it should show the aliens as good. It seems Hollywood has to get out of its fear-mongering spell and start showing the machines and aliens as good, and humans as inferior beings that need to learn.