Uhm. I thought the Alien presence clearly warned along the lines of - if you reject us, we'll leave your world and take all of our technology with us?
They never explicitly said that it'd take away the technology, though it was somewhat implied by them mentioning how their presence had improved Earth's technology. The main clue is that when they give up they say that humans "will be left to their own devices", though that's not exactly a threat and also a bit too vague to definitely mean "no more technology for you", hence the ambiguity.
Im not sure I buy the "human oppressors" bit, or that the robots are wholly lacking in culpability bit. The whole "I'm a thinking, reasoning person, but I acted under duress from my master," is rather vague, and the movie didnt really dig too deep to even set up a real storyline for the robots-created-by-alien-intelligence. We dont know enough about them to really make an informed decision that they are emotional feeling beings that "wish they didnt have to do what they were made to do."
"Human oppressors" was a bit much on my part. It's never quite shown how much of the human population actually accepts the robots - it seems like some time passes during the events epilogue and while crowds of humans angrily abuse the robots at first, eventually there are scenes of them learning to accept the robots and co-exist with them and that the ones who still hate them do so out of stubborn prejudice. As for the robots' culpability - well, they are machines. The idea seems to be that the Network removes their capacity for free will and they are programmed to either go about a normal routine based on their human counterpart, react to misbehaving humans (the kid in the toilet) or simply get hijacked by the Network to follow orders (every scene after the big bar brawl, as signified by their glowing eyes and all of them doing the exact same thing). There are hints of emotion to them - when Gary provokes the aforementioned kid in the toilet, the kid gently tells Gary "Please stop, you don't want to do this" but when Gary persists the kid's robot instincts take over and he tries to kill Gary.
That whole aspect of the film was hokey and unrealistic, because they really dont flesh out the robot backstory in any real way. Where did they come from? (Aliens) How were they made? Are they "just" robots or are they emotional beings, "a la Almost Human" and a host of other relatively thoughtful films that explore how AIs can become sentient? Now, if you had told me they were human CLONES, or an enslaved race of aliens that can be made to morph into another person once in their lives and then they are stuck as that person - another story.
I think the robots' back-story was fleshed out just fine. They were built by aliens (who may or may not be robotic themselves). How they're actually built is somewhat irrelevant, but the best explanation seems to be that they're cyborgs - since it's revealed that the robots are cloned from DNA samples, the likely story is that they're artificially grown in vats like the ones seen in the last pub. Granted, whether they're legitimately "emotional" is never explicitly confirmed, though in my last paragraph I mentioned implications that they seemed to be (although that was suppressed under the Network's command). The only robots we really get to see after the Network leaves (aside from the crowds of robots getting attacked by humans) either return to their old human lives or join up with Gary, which can be read as either their own free will or mechanical routine. There is evidence for both conclusions, really.
As for the robots being changed to actual human clones or shapeshifting alien slaves...well, the human clones thing might work but it wouldn't make for some of the cool visuals and action potential provided by robots with blue blood, glowing eyes and easily detachable body parts (plus how would they controlled and unified? Brainwashing, perhaps, but the Network being able to use basic remote control to do it makes just as much sense). The shapeshifting alien slaves concept would not only generate just as many plot holes as the original robots did, but it also doesn't make sense considering the Network's goal. The Network's goal is to "perfect" the human race by forcing them to either behave properly or by replacing them with an identical copy that still retains some of the same memories. Alien slaves make no sense because while they might be able to copy a human's appearance, underneath it they still have the mind of an alien slave. Changing the aliens' motive wouldn't work because "evil world domination through genocide and slavery" is far less complex/interesting/sensible than "morally ambiguous world domination through convincing humans to conform for cool rewards or else be turned into a robot anyway".
To go all "Gary is just a decent guy standing up for poor, picked on people. Gary is their Saviour" is a bit too much me. Specially when the person he's saving (by drinking and bashing heads in) is...oh dear...a younger version himself. Its very self-focused, self-serving, and self-aggrandizing, which we know he is prone to do.
Simon Pegg's Cornetto protagonists never really do a complete 180 in their character development by the end of the movie. Shaun learns to be a caring, responsible boyfriend but still keeps the zombie version of his troublemaking best friend out back because even after everything he still loves him. Angel learns to make friends and lighten up but he still gets his team to fill out massive amounts of paperwork at the end because that's what the police are supposed to do. Gary follows the pattern in that he learns to stop being completely selfish (plus he apparently quits drinking because he orders water instead of beer at the end), but he's still willing to chase a good time. His friends may be robots, but they're still his friends (even if it's not entirely their choice) and if the bar patrons are not willing to let them have a good time simply because they're robots then he has to do the morally right thing and fight for their right to party. Sure, it's self-aggrandising in its way (just look at the way he calls himself "The King" before starting the fight) but it's motivated just as much by a need to stop ignorant bullying, if only to stop the part getting ruined. Nobody said he had to be perfect by the end.
Also, in terms of leading the group of boys - I'm probably biased because of nuture, but I come from a large family, and I'll never forget something my parents taught me: to lead a group of people younger than you is easy - you are already larger, stronger, richer, more knowledgeable and probably less afraid than they are. To lead people younger than you can be done by sheer force of personal charisma and hero worship. The real challenge - thus the real nature of a man (or woman), can be determined by their ability to lead actual peers. A person's peers are people who stand on equal footing, and have less to gain by following you. To lead them you must actually command their respect. To be a big fish in a small pond is easy - you just race to the bottom, and stay there, or in Gary's case - never leave it. To ever be a big fish in a big pond(?), you actually have to face the difficulty and fear of leaving the small pond, and potentially being a small, or average-sized fish in a pond of fish much larger than you. Real leadership is made there.
To me, Gary.... almost made his way into the big pond by reconciling with his friends, and becoming a contributing member of society, but in the epilogue, chose the small pond again - running around with the riffraff, on the fringes of society - just like he did before the pub crawl and alien exit. What happens when they actually meet a force they cannot overcome - Gary's gonna be back in gutter, back on the bottle, probably slitting his wrists again. That's my theory anyway.
That's actually interesting considering the fact that the only way Gary gets to lead his same-aged peers on the crawl in the first place is by shamelessly manipulating all of them into going along with it. Over the course of the film he learns to stop being so selfish and irresponsible (though he still has his lapses) and by the end he actually tells his friends to stop following him because he realises he's not a good leader but they still do it anyway because in spite of everything they still have some respect for him. When the world ends and the others go back to rebuilding their own lives, he respects that and doesn't even ask them to follow him again. Like I mentioned before, Gary undergoes character development but making it so that he gives up his free-spirited ways and settles down just seems too out-of-character to be believable. It's kind of like the ending of
Mad Max 2 where Max saves the colonists but he realises he's got no place in their new world so he disappears back into the wasteland and they never see him again. There's character development and then there's being true to the character. Also, if Gary's behaviour in the very last scene of the film is any indication, he's not likely to relapse into substance abuse or suicide. He orders water instead of beer and seems more willing to die fighting for what he believes in than to let himself give up and attempt suicide again.
The whole thing is a farce anyway, because there would be no reason to have robots of them at a young age, because if they were going to be replaced, it would be by robot clones their own age, right? The film makes leaps in even speculative logic, and is downright hokey.
The Network wanted to convince Gary to give up and join them and to do that they offered him the one thing he's been chasing for the whole film - the chance to be his younger self again and forget a lifetime of misery. Making young versions of Gary's friends that still idolise him instead of hating him was meant to sweeten the deal.
But for real tho - I recognize Im probably overthinking a simple fun film - but I cant help it!! LOL Not meaning to get too heavy, or crush your enjoyment of the film.
it's not a problem, I'm actually enjoying this discussion anyway. Always good to see a challenging, well-argued perspective, especially if it makes me reconsider my opinions or at least gives me good reason to argue my case. It's all in good fun, anyway.
Now it's 4:30 a.m. and I've once again taken ages to write a mammoth response.