Yes, because at least the Legion has potential to change. The NCR is fucked no matter what. And despite their faults, because of the Legion, places like Arizona and Mexico City are some of the safest places in America. As long as you don't try to sell chems or alcohol, it's a great place for merchants, who don't even need guards in their land. And, as said by Caesar and shown in the ending where he's alive, the Legion starts the chill the fuck out. Caesar admits that they're basically nomadic raiders, and says they won't need to be once they take the dam and New Vegas because, as Caesar states, "They will finally have their Rome." Something akin to that.