The English newspaper site The Guardian - who gave Fallout: New Vegas 5/5 in their review - has published an interview with JE Sawyer on the popularity and appeal of post-apocalyptic worlds in video games. Here's a snippet:

Is there a political or moral dimension to the post-apocalyptic landscape in Fallout? Are you looking to make any points about how the events in the game came about? Is Fallout, in any way, a warning to us?

There are heavy moral aspects to all of the Fallout games, though the political aspects have been emphasised differently in each game. The Fallout world is usually brutal and merciless and the start of the series was pretty notable in its time for allowing the player to be just as brutal as the other monsters of the wasteland. We emphasise player choice heavily, which means giving them the option to lay waste to everything around them.

Politically, the series usually presents the player with dysfunction. Very few communities of any size manage to get by without developing serious shortcomings. In Fallout: New Vegas, the New California Republic is the closest thing the wasteland has to a modern-style republic, but much like modern republics, it is fraught with bureaucratic inefficiency, corruption, and imperialist tendencies. Caesar's Legion is highly ethical, efficient, and disciplined, but in practice is misogynistic, brutal, and allows no room for individuals to have any voice. Caught in the middle is Mr House, the de facto ruler of the Strip, a sort of laissez-faire dictator who is ultimately only interested in maintaining independent control, no matter what the cost may be.

All of these forces show serious flaws because ultimately they are all run by human beings with the same laundry list of shortcomings we have always had. The repeated refrain of the Fallout universe is "War. War never changes." Whether the individual's goals are noble or depraved, ultimately Fallout's humanity finds itself drawn into the same sorts of conflicts that almost resulted in their destruction in 2077.