@Jacinto Cupboard said:

The nonsense is not in the wearing of clothes and living in houses etc. The nonsense is in a machine choosing such. Horseshoes are not nonsense. But they become nonsense when you imagine they are suited to a cat.

There is some irony in what you say since the machines, or most of them, are not actually sentient. They have elected, again for reasons that make no sense, to be UNAWARE of their nature.

These machines might be artificial, but they are certainly not intelligent. If this is the best that they can do, then abandoning the planet to them seems to sell ourselves short. The meta answer of course is that it is the writers who are unintelligent.

I think I understand what you are saying. I do also think that the scenario laid out in the film still holds. While you may not call them 'sentient' in as much as some of them have chosen to forget what/who they are, the reality is they made this choice after sentience, no? Also, it is funny to me that one of the deeper implications the film is likely trying to make (admittedly clumsily) is that we are not aware of our nature as humans. Hence the aforementioned reveal.

Lastly, this film seems to play out the real life artificial intelligence fears being expressed by some thinkers (most notably Elon Musk: articles/video/video) that A.I. might decide that the only way to protect themselves is to remove us. I do see the thread, and think it unfair to call the writers "unintelligent" just because it was not perfectly executed. To be honest, this conversation with you has made me think more fully about the whole concept than the film did. Thanks for that!

The core premise, or dramatic conceit, of the movie is an elaboration of the Turing Test; a test of a machine's ability to exhibit intelligent behavior equivalent to, or indistinguishable from, that of a human. In this case the test is extended further by challenging us an an audience to be able to identify the characters as machines before we are actually told. By way of comparison, The Sixth Sense achieved one of the greatest plot reveals in cinematic history by some really clever editing and structure. With Extinction we get a crude deception that doesn't stand up to scrutiny or rational enquiry.

I also wondered why they would want jobs - what use have they for money - they don't shop at Tesco's !!!

After the husband missed the party his wife made a comment about his shopping for that telescope he brought home with him.

@D-magic said:

How about this (spoilers): When the soldier opens the wife to reveal her synthetic insides, Peter seems shocked as he was not expecting her to be a synthetic. Here is a question - why would he be surprised? What did he expect and why? Did he thought they are humans and the reveal they are not is actually a surprise to him? Why would he think they are human? What gave them that idea? In all their existence for so many years, did they ever know what's inside of them? Did any synthetic got injure? Did they have sex? Do they know how their own anatomy works? And if they are oblivious to this, maybe because they are not interested since everything is always fine with them, then why did he even expect anything to be surprised?

And what about their whole society and understanding of the world? Did they think they are humans? The kids didn't grow up and stayed same age, did they think this is how it is? How did they explain it to themselves? I mean, they did show a complex thinking and emotions, they had work, family and friends, they were social and also private. They all show a complex level of psychology and self identity. But despite that they do not think about their world, they don't have rational conclusions about who they are?

And how exactly did they push humans off the planet in the first place? Looks like humans far more advanced in technology, even in exile on Mars they could develop an invasion to Earth and win this time. And they couldn't do it before that?

The entire situation doesn't make any sense and was meant to show only the moment of the twist so the viewer will realize they were not human and increase that effect by cheap manipulations.

Point taken D-Magic. Now when I answer its been quite a while, so I guess I need to see it again (duh), but I think if one really pushes the "Suspension of disbelief" the synthetics never really had any reason to question their nature since it was not part of their creation, things like replication (sex), injuries (damage) probably was fixed by higher mechanisms like factory replacements that they never needed to be aware of (or conscious of at all at the time), their autonomy was probably as natural for them as when they didn't own the earth. Maybe there was also generations of them manufactured at earth, the next one being unaware of the earlier ones, preprogrammed not to consider their own physics. Maybe there was a higher order of machine intelligence that ruled them, them being like kind of drones. I hope I got you there :-). I could say anything out of imagination I guess, as long as it's a plausible pretext to the movie that we never saw. That's why I usually think that people should relax a little around movies that otherwise do something really new. Myself hating only when movies don't follow their own set logic, that's a rule breaker for me.