Thanks for the sighting! "Who is John Galt?" has been within popular culture for two full generations now. Granted that the Bush-Obama bailouts in the wake of the mortgage meltdown really triggered a surge in sales, when you look at total book sales over time, it is the kind of thing that any literate person knows about, even if they never actually read the book. And when it comes to gamers, they revel in the social fringes, excel at arcania.
Just a note, though: when you said "Blizzard" I thought that you were referring to a fast food drink.