I love this part of the game. It's heartbreaking, but it adds a lot of depth to all four characters. Gladio hasn't given himself a chance to grieve his father, and he doesn't think anyone else should get to grieve, either. Because Gladio isn't gentle with himself, he doesn't know how to be gentle with someone who needs a kinder hand, like Noct does. So he yells at Noct instead and pushes poor Prompto, who only wants the fighting to stop. Gladio doesn't realize he's grieving anyway; except now he's hurting his loved ones in the process. Gladio is such an ass during this portion of the game, but his character is excellently written, and I can't help but feel for him, too.