I'm pretty sure she gave him the choice...It's kinda of sad when the ARG set up to promote the game has a better storyline than the game itself. I'd have rather played THAT story as a game instead of this one.
Poor Mark Meltzer. Went through all that trouble to find his daughter, only to find out she's been turned into a Little Sister. Then Lamb turns him into a Big Daddy, so he could always protect her... at his request. Damn man... that's better than all of this crap about Johnny Topside.
But i was disappointed that you didn't get to meet him except as a corpse...