Deconstructed: Tom tries to convince Chris out of his cynicism and Chris says he might have a point. After all a true cynic is cynical about their own cynicism.
The idealists realize that offensive tactics and anger are worst ways to disprove cynicism, because cynicism is, after all, anger and hatred manifested as a form of philosophy, and any insult directed at it will simply be assimilated. In order to justify that cynicism is for losers, they have to prove it realistically.
Chris admits that he's pathetic loser...and he's content with that, much to the disgust of others, not that he cares what they think.
Played For Drama:
Chris' cynicism got so bad that he ultimately ends up crossing the Moral Event Horizon, screwing over one of Tom and the other's plans and getting Alice killed, all for his own gain. He tells them they were wasting their time with pointless ideals when confronted and he saw an opportunity to actually gain from the situation. That's all. Enraged, Tom and the rest of the idealists strand him, leaving him to fend for himself out in the wild without any of the laws and courtesy of society that Chris held in such contempt. However, this leads to Chris being more justified than ever in his conviction that the world is a Crapsack World, thanks to the betrayal and the experiences in the Crapsack World that is the wild. Thanks to having to fend for himself, he is physically stronger now as well, and hungry for revenge...