Why do people take this so literally?

Yes this film is very powerful, especially in its imagery (that awesome shot of the "horseman of the apocalypse"-style rider near the end, for example).

BUT its not supposed to be taken literally.

This films purpose is to provide background information on the Matrix universe, and is not meant in any speculative way. Its an extremely unlikely scenario.

Think of it as similar to Platos analogy of Atlantis, which was invented by him to demonstrate his philosophical theory. Now we get people taking the "lost continent" literally and going out to find it, ffs. A more controversial example would be the Bible.

This film was made as a warning against handing over our thinking to machines, which of course is a dangerous trend and one to be avoided. I am not, however, going to have sleepless nights over the machines taking over, or of mankind filling the skies with some sort of gas yet to be discovered.

So please people, see it for what it is: science-fiction with a message.