In today's podcast, the crew talked about how bioshock infinite "not earning" the racial elements to the game and that is was trying to say something, but it didn't. I read somewhere at some point that this game was created by first creating the world and then the story of the game. In this context, it's clear that the racial elements are for showing how bad the world is and is another motivation to kill Comstock. It's not Irrational making a half assed attempt at saying something about racism, it's just a backdrop for the story to take place in. Thanks for reading and disagreements are very welcome!
P.S. as you can tell i'm not a very good writer so if you need clarification on what I said, please ask.