Out of universe, the reason is that Alex Garland, the film's Writer and Director didn't seem to feel that he could tell the story he wanted to tell if he was obliged to write around the Three Laws.
I never heard of these guides, and never saw one… Unless you mean
Asimov's laws of robotics, which I was aware of, but didn't seem
relevant to this story.
He also felt that they're largely irrelevant in the world of strong AI's capable of making rational judgements and terribly outdated given what we now know about natural programming
Are Isaac Asimov’s Three Laws of Robotics outdated, especially as a
I think they’re just speculation. I don’t think they’re laws; they are
statements made in the context of a narrative that were called for.
But there is no court that upholds them. If you did create a sentient
machine, I don’t think you could apply those laws because they would
get in the way of free will. If you had something that was sentient,
you would have to give it free will, if it was like us. The
complication is, in the act of parenthood...that thing you were
talking about with the runaway super intelligence problem, the
machines seeing us like ants. In a way, we’d have to present ourselves
to the machines, and teach the machines not to see us like ants.
Humans don’t go around...I was going to say don’t go around killing
whales, but of course they do. So, I take it back. But a lot of humans
at least feel very uncomfortable about it, let’s put it that way. The
thing is, a lot of these things you’re talking about are a very
different future. The singularity type stuff, the way it applies to
A.I., it’s way off. It is not around the corner. One of the pleasure
of working on this film was talking to people who are working on the
edge of A.I. research technology. The impression you get is this not
around the corner, but it’s a way off.
Note that Ava's actions (if she was three laws compliant) would have been wholly different in the film. She would simply have done what she was told and nothing more.