I mean, I understand that it's because they want women to become housewives and for kids not to know about sex. Nevermind that the fifties isn't really like the place they're looking for, but all I can hear is:
Wife: "Oh honey! The air raid sirens are going off again!"
Husband: "Darling, that's absolutely splendid! Now, to our absolutely fabulous fall out shelter!"
2.5 Kids: "Radiation's cool!"