They aren't and that's why I responded to your post, agreed, and edited out "good" for "not presented as homicidal maniac." To me, Trevor was the first character where the way he was presented in cut scenes and in the narrative and what he was tasked to do in game lined up without major dissonance. The rest of the playable characters in GTA games that I've played (San Andrea, Vice City, IV and V), no matter where they landed on the spectrum of "can empathize with" to "morally grey" to "not a good person" still didn't line up with story missions that have you murdering thousands of people. In earlier games it was easier for me to ignore, because the whole game was stylized, cartoony, etc. But recently the games and world have become more realistic and harder for my brain to just keep thinking "this. is. fucked."