I rewatched it.
First, the question “Why?” Why save the world as it’s become? As Koumba says, no crime no war no racism.
Carol is taken aback: aren’t people supposed to want to save the world?
But thinking about it, perhaps their motivation isn’t world peace.
I hope we get some sort of flashback episode where we learn more about them before - but perhaps their motivations are more basic: Koumba’s situation has improved tremendously: as a bon vivant, he has his favorite foods, a harem, AF1, the penthouse suite, anything he wants. We don’t know if he lost loved ones in the Joining and how he’s been affected but from what info we do have he doesn’t have any reason to want to return to a pre-Joining situation. And maybe he’ll tire of rigged games etc but that early he must be ecstatic.
(Fun fact: I set the French subtitles this time around and learned “s.o to peel your grapes” is “s.o to butter your baguette slices” in French “beurrer tes tartines”).
Everyone else still has family members. It’s only 2 days after the joining so they’re not in mourning, they’re in denial, and having pretend-alive wife, pretend-alive son, pretend-alive mother… May be a coping mechanism. They can’t hear that their loved ones are dead. And they may not be, since their memories still exist within the Hive and they can continue being actors close to the OG individuals. And, really, ARE THEY? Since their memories still live through them?
Also, 886 million people have died to reach world peace? 
How is that even acceptable?
Then again Carol herself has killed 11 million people.
But officially they’re not really dead since they’re inside the Hive.
Which sounds a bit religious. Like, your body is dead but your soul lives.
But still you’re dead and others mourn you.
Is joining like committing suicide?
Would YOU want to join?