No when you are fighting for something that will gain you something it is no longer grey. It is not mercenary work, it is not soldier work, and ironically, not warrior either. It's just "Do this and your family gets to live in luxury and if you fail, they die, because we will kill them" and that's all cool UNTIL you are killing other families, thefore it doesn't matter, because you already killed more that you saved. The one thing that could be seen as "grey" is the Children of the Devil thing?
(2) But then do you buy into that crap? For one Historia already rejected the Progenitor, and Eren can’t even use it! The whole reason as to why Bertolt could be justified is because King Reiss/Fritz could potentially destroy the world. But even then, why not just kill Eren and be done with it? No more Progenitor, no one to awaken the Colossals. Yet it seemed like Bertolt wanted to kill all the Wall People, because he thinks they’re all capable of great evil like their ancestors, which is bullshit.
Ahhh, yes, I totally forgot the part where five year old baby Bertholdt was sitting in his labor camp preschool and suddenly decided to walk into a Marlayan military facility to willingly submit to years of brainwashing so he could grow up to become a mass murderer. Tsk, tsk. Silly me.
Seriously, what’s it gonna take for Bert to get a little sympathy?
Bert and Reiner didn’t know that Historia rejected the power. They didn’t know that Eren can’t use it. Their mission is “retrieve the coordinate and end the cursed history” - a history that they believe involves an evil king who is coming to kill the Marlayans and Eldians and reinstitute a corrupt regime that involves subjugation and ethnic cleansing.
And exactly who in this story is completely altruistic? Who is operating purely for the good of the nebulous world of humanity? I’ll tell you who. No one. “Cool motive still murder” applies to basically everyone in this story. How is fighting to save your family and your nation any less noble than fighting to see the ocean? Or fighting to breathe the air outside the walls? Or fighting to save the one person you love most?
I’m not justifying what they did. It was wrong and evil - that much is black and white. But as individuals, they are gray. And they are worthy of some compassion.