I have to imagine that Kratos got old and annoying to even a lot of the people at SSM. I have always been a big GoW fan and even I got fed up with his personality.
GoW1: Man, this Kratos guy sure has it rough. Ares is a dick. Yeah, let's bring down this asshole. Wait, the Gods went back on their deal? That's messed up. Weird that they made him a god though.
GoW2: Okay, maybe Kratos took the war stuff a bit too far, but killing him like that is pretty fucked up. Couldn't we have talked about this instead? Killing Zeus seems pretty serious, but he did kinda start it. Oh shit, he killed his only ally, Athena. See Kratos, this is really going too far. Wait, you brought back the Titans? Holy shit, this is getting crazy.
GoW3: Alright, so we're going to just take care of Zeus. He's really the only one we have a vendetta against. Wait, stop killing literally everybody, Kratos! What the hell is wrong with you?! What are you even mad about?! You just blotted out the sun, flooded the lands and freed the dead. Stop it!!! Dude, you just killed Hephestus for trying to protect his daughter! And now you're going to protect her?! Zeus was right, you're a monster that needs to be put down. All you do is bitch about your family and being mistreated. That really sucks, but man you suck. I don't want to hear your problems anymore. Just stay away from me.