-...considering her life: Growing up in a war zone, losing her parents to violence, being experimented on and manipulated by Hydra, being manipulated and betrayed by Ultron, losing her brother, accidentally killing all those Wakandans, being tortured on the Raft, losing her robo-boyfriend, going crazy and creating and losing her kids...There was no way her story wasn't going to end in villainy.
Plus, y'know, the Darkhold. That thing drove an LMD crazy in Agents of SHIELD.