Warning: This page contains major BioShock spoilers. Proceed at your own game-ruining risk!
You are a programmed slave
Why do videogame heroes always do whatever anyone tells them? If you somehow ended up in Rapture, would you stick around to help save the godforsaken place? Of course not!
But in BioShock, you don't have a choice. You see, Atlas / Fontaine didn't just lie to you. He brainwashed you, programmed you to respond like Pavlov's dog to any verbal command he felt like giving. "Would you kindly?" - his catchphrase - is not a polite request. It's an order, a psychological trigger phrase that pushes you into submission.
Gives new meaning to the mysterious chains tattooed on your wrists, doesn't it? Watch Andrew Ryan mock your pathetic lack of free will in the clip below.