One thing to me is funny how you compare GTA to AOT

In games ppl feel less about NPC as they will re-spawn or you can load a save to have them alive, so ppl can fuck around whit the NPCs when they are bored or feel like it, or just experiment whit the game. Plus GTA is a parody of american culture and you are encourage to kill em (he the story in that game is about robbing and killing almost anyone, you are playing as a bad guy there after all)

AOT is set in a much darker theme and constantly gives gray choices, killing of ppl wich would never come back, eren is presented as the good guy early on, but becomes the bad guy who wants to kill everyone

The massive problem whit his idea i have and others is him killing innocents folk in the AOT, if its just the jegarist fighting against the world armies, a lot of ppl wouldn't care as both sides are bad. But eren killing the innocent is what made his friends go against him and why ppl have problem whit the whole genocide thing