The Allegory (plus District 9)
Where Blomkamp's District 9 skewered apartheid and general racism, Elysium goes after immigration and the poor treatment of third-world countries by the developed world. I think there's a lot of important things to be said there, but the film falls a little flat because it doesn't accurately portray what's going on.
District 9 accurately portrays racism. There is a group that's not "our" group. They look different, have odd (to us) customs and habits. So, we hurt them, corral them, give in to our fears, and try and profit by them (use of their tech in the film), but keep them at arm's length, at best, while hurting them.
That *is* racism. That's how it's always played out and continues to play out.
Elysium doesn't work because the resources in the film are portrayed as infinite. There are good reasons to have an immigration process. You can't just "heal everybody". You couldn't import every human from Earth into the ring and have the ring function. They'd be jammed in like sardines. Resources are limited.
I think the film is strongest portraying stuff like the "do the poorly-paid, dangerous work and like it (because there's nowhere else to go)," and the brutal treatment of the "lower classes" and the "other", but it falls flat because when it tries to drive home points about immigration and integration, it's not being honest with how that stuff works.
There are ways to satirize, criticize, or portray the stupid, senseless, thuggish policies around this stuff, but this comes off as half-baked.