Shinn has a personal grudge against Kagari, which might not be too admirable since I doubt (and I don't really think Shinn believes so either) that Kagari wanted anyone to die. Regardless, that doesn't change the fact that Kagari acts like nothing is too much of a deal and in fact she complains a lot more than Shinn does (about ZAFT having weapons etc etc). If Kagari only started acting like a veteran or at least saying to Shinn that it wasn't her intent for any of the shit to happen, perhaps Shinn wouldn't complain so much. Until then, I don't pity Kagari at all. Shinn is right. Athla sugercoated everything, people died. He has the right to complain.

Edit: I don't want Kagari to be removed from the series. I just don't understand why people complain about Shinn's treating of her so much. I mean, imagine Shinn's damn situation.

And he's hardly just a kid with a paranoia problem, he is the pilot of the Impulse for a reason being that he is a good pilot and a reliable person. But in reflection to what people here seem to think, being a great pilot seems to reduce a person's every right to bash others for saying naive things.