examples of characters who did bad things for justifiable reasons out of their control: Jack Ryan/Wynand, Songbird, Bastion

examples of characters whose actions were influenced by a negative environment but still made those decisions with a clear head and full intent: Booker Dewitt, E-001/Eveline

in terms of eveline tho there seems to be a split issue here. a lot of people say that she's just a kid who didn't know any better. "she just wanted a family" nah she wanted a dollhouse that imagery is all over the place m'dude (remember the giant doll at the table in the final chase scene through the guest house)

honestly tho eveline's programming does affect her urges and innate desires (such as wanting to spread her influence like a fungus would and likely the whole family obsession) but imo she's just a bratty kid who happened to house a dangerous bioweapon she 2000% knew what she was doing

"why does everyone hate me??" idk ask the hundreds of mold zombies living in your basement that you instructed the bakers to kidnap with complete control over your actions

songbird is also a common confusion here and honestly since we don't get much info on him it could honestly go either way but i'm 100% on the "he was a victim just like elizabeth" train. like,,, remember when elizabeth said the C-A-G-E code word on the Hand of the Prophet? he slumped over. his body language loosened and became less rigid. him doing all that stuff for elizabeth and protecting her wasn't because she'd just swapped who the brainwashing was favoring in terms of controlling him, it was because she'd broken the brainwashing and he was acting of his own volition. remember that her exact words were "Can you do this for me, this one last thing?" that's a nonspecific question, not an exact command like the ones given to jack, an actual brainwashing victim. consider "Would you kindly head to Ryan's office and kill [him?]" as opposed to "Can you do this for me, this one last thing?" the first is exact: go here to kill him. the last one requires cognitive, independent thought to even process the question: he has to understand his environment and the current threats to even know what the word "this" is referring to and it's phrased as a question that's more asking whether he's willing to. the only command Elizabeth gives it when she's trying to get him to leave her ("Go go go!").

people often cite the beginning of the ending as a point towards songbird being against them all along. booker drops the flute and says "The bird, Elizabeth! I lost control, he's coming!" songbird then flies towards them. however, if you pay attention to his motions just as he's approaching, he isn't planning to ram them like he does to attack the Vox. He pulls up to land in front of them (although this might also be him recoiling to avoid Liz's tear, but at this point I think the action was too early for him to be doing anything besides trying to land). "Then why kill him?" you might ask, as literally just afterwards Elizabeth drowns him through a tear. I'm not sure, but I think it's either because she knew that he was in pain (he was modeled after a Big Daddy and given their method of creation every step has to be absolute agony) and wanted to put him down easily or that she knew Columbia was going to either be destroyed or abandoned and that he had no other place in the world and would be alone forever if he was left behind. Also, since he's bonded to her, there's also the chance that he'd go crazy and die like the Alpha series BD's did. 

this was supposed to be short oops i just love songbird he deserves better