The nuclear war happens in 2077.
Fallout 3 happens in 2277.
During those 200 years people in DC don't just fail to rebuild civilization. They even fail to get rid of the random pre-war garbage inside their own homes!
New Vegas (which starts in 2281) is better but still way too post-apocalyptic. I want my Fallouts to be post-apocalyptic but they should have been set much sooner after the war (maybe 70 years, just long enough that almost no one who remembers the pre-war world is left) and even then settled people shouldn't live in shacks.