They're a dark nation that the wasteland needs to bring peace to the world and for society to rebuild under one rule.
I broke your argument.
edit: I am not an NCR fan myself because they repeat mistakes from before the war but I am impressed by the way they have managed to become so big that it'll take something very significant to bring them down. Personally I thought Mr House's vision for the future (for the ends he has in mind) was cool because obviously the guy is a long term planner and what mankind needs is a few more visionaries like him