Why does the fallout games take place in the future but it looks like the past?

I wondered about that at first - but then I figured it out later. Here's a better description than I could make up:

"Fallout is a computer role-playing game produced by Tim Cain and published by Interplay in 1997. The game has a post-apocalyptic setting in the late 22nd century, though its story and artwork are heavily influenced by the post-World War II nuclear paranoia of the 1950s."

ok heres kinda the backround w/o ruining story. there are people during the 1950's that were the elite of the nation etc that were paranoid of a nuclear war so they built vaults and shelters and went in them when things went sour. The nuclear bombs went off destroyed civilization mostly hence most of the technology and remnants are things that were last developed in the 1950's, something causes you to get out of the vault and hence you've lived in a bubble world where everything is from 1950's. Thats the basic backround, hope you enjoy the game when the new one comes out ^.^ and play the old ones they are sooo awesome.

It takes place in the 50's with a few sci-fi elements after the world has been nuked.

***