The problem with setting Fallout 3 being set 60 years after the bombs would be that there couldn't be the Brotherhood of Steel and Enclave in the game.
Well that's another problem with FO3, .
The real problem with Bethesda producing FO3 is this...
they made a popular PC title (though commercially having limited success) into a mass market product.
Did they do a good job, well objectively it is a fine game. If one disregards the first two parts an excellent job. The game is fluid, really embraces the post apocalyptic feel etc.. (Yes I am being cynical), but objectively this is how many will see the game)
The real problem is that they made a game which took risks...and still was successful and made it their own. They copied what they felt were the most important elements and made a very safe mass market game.
1. Drug use: It is basically potions.. but with risks of getting addicted..
2. advlt themes: I don't need to see six in cg... but sleaze is part of parts of the world... FO:NV understands this better.
3. VATS is not a turn based compromise...In an FPS (even if dicerolls decide hits) aiming will take the edge over strategy. VATS is simply an easy alternative.
4. They made the games (FOII in particular) factions very black and white. IMHO not because they didn't understand the lore, but to play it safe. So ... the main antagonist in FO2 became like the nazi's (even though, their main philosophy could be followed following the previous game), BOS had the coolest armor, so let's make them gooooood and add a big robot to boot.
5. The bombs fell like 200 years ago...but lets make people feel like they fell yesterday and that we basically give you.... MAD MAX II the RPG..