RJ 17 said:
Right before you open that final door and revisit the baptism site, Elizabeth even turns to you and asks you "Are you sure you want to do this?" to which you say "Of course". Didn't THAT, if nothing else, spawn a universe in which Booker says "Actually, fuck this. Please, let's get the hell out of here. We can go to Paris or where ever you want but I just want to leave this mess behind me"?
This decision puzzles me as well. The best I can offer as an explanation of why the set of universes that result from Dewitt?s decision are limited to him going through the door is the discussion Elizabeth and Booker have when walking among the lighthouses in the sun:
Elizabeth: Look!
Booker: It's us.
Elizabeth: Not exactly. We swim in different oceans but land on the same shore. It always starts with a lighthouse.
Booker: I don?t understand.
Elizabeth: We don?t need to. It?ll happen all the same.
Booker: Why?
Elizabeth: Because it does. Because it has. Because it will.
Booker: There are so many choices
Elizabeth: They all lead us to the same place... where it started.
Booker: No one tells me where to go.
Elizabeth: Booker, you?ve already been.
It is worth noting that the Elizabeths at the end disappear, having removed the possibility of the universes that spawned them ever existing. That would only occur if at least every version of Dewitt that goes on to become Comstock is drowned. It would certainly happen if, as I said earlier, every version of Dewitt is drowned (both theories yield the same after-the-credits result but I feel the latter better fits with what Elizabeth says).
Perhaps we have reason to doubt the intended meaning of the multiple-Elizabeths scene an whether the Dewitt you play as represents them all, but I confess that at this point in the exploration of what happened I am content to move on. What interests me more than any of this is what the game tries to say in a broader sense. I have my own thoughts on it and would be very interested to hear what others think.
The protagonist was a bad person from the outset no matter what version of him is examined. He is offered a deal to wipe away his wrongs but the deal is just the next step in a progression toward destruction. His past wrongs (before the baptism occurs) cannot be undone and attempts to do so are futile.
So then what do the events of the game, as a whole, represent or teach?
That trumped up, vicarious, redemption is no redemption at all; that the past cannot be undone; that the future is a realm of possibility in which we are free to live a different way while still bearing responsibility for our past.
I think it is extraordinary that some people have said the racial elements in the game aren't relevant to the overall message. To play Bioshock Infinite is to play out an impossible narrative in which the protagionist both struggles against and accepts his own fate. Indeed, the frequent references to constants and variables prompt the player to examine the very nature of self-determination. Themes of racial suppression and conflict tied in very nicely, I thought.