Kanda being all sweet and sour always gets me by surprise.
I kinda agree and even have the same opinion... but at the same time, I don't entirely dismiss Chaoji's point of view after thinking about it a little.
He certainly adopts a one-track mindset on this situation, but... Chaoji grew up knowing the pains of this war and then... he lost the people that were his family to it, yet again.
His first reaction to Allen's way of life was pretty extreme... but he kinda was vindicated when Tikky proved that yeah... the Noah are more trouble than Allen thought.
And there is the parasite that is in his body now, and everything till now that has been shown about it says that the parasite can manipulate his mind, so maybe his present state of mind isn't completely his fault, sure... the original opinion still his, but if an alien body is strengthening such feelings he may isn't entirely at fault.
Point is... I just don't want him to die before he can see things in a new light, for all his salty behavior, he is being used by the Noahs and just as easily they will squash him and not even spare a thought to it.
As much as I "like" many of the Noah, they still think nothing of people's lives, their apparent "fondness" of Allen does not extend to other people.