And like I said before, the Vault Hunters and the people of Sanctuary aren't THAT bad. For all their moral faults, Axton, Salvador and Brick are played for laughs, and Maya, Gaige, Roland and Lilith are pretty much pure heroes.
I too, kept trying to tell myself Jack was a good guy, and that's what I loved about the story of Borderlands 2... You constantly wonder if you're the good guys or the bad guys, because Jack claims to be the good guy and they set it up so that you question whether he's right or not. Unfortunately, even if you boil it down to a contest of the lesser of two evils, we're still on the good side.
After everything Jack has done, forcing Angel into slavery ever since her childhood, slaughtering anyone who faced him, I'm kind of curious to how he came into power in the first place.
The game is very tongue in cheek. Jack is an entertaining villain because he is not the typical dark brooding figure that most bad guys are. He engages with you , mocks and taunts you throughout the whole game. He is evil but he is also very chatty and genuinely funny in a horribly cruel way.
The games moral compass is completely broken in a way you like in a game.
The Vault Hunters steal and kill almost everything in sight with little to no justification just like Jack, the only difference is Jack actually thinks he's some sort of hero and that's perhaps why he has to die most of all.