Maybe if they all converted to Judaism it would work, too, but that doesn't even seem remotely possible so it wasn't mentioned.
Of course, if they all converted to objectivism, they would be even more successful.
I agree Im basically an objectivist I have 2 main disagreements( 1. I only believe forced altruism is evil 2. There is such a thing as rational religion ie the universe existing in time must have a cause outside of time or else the timeline goes back forever with no point of origin).