I think I know why. In the fifties there was a very intensive civil defense initiative doing just that, teaching people the basics of responding to a nuclear attack.
Unfortunately, those "duck and cover" ads were parodied mercilessly by Hollywood and the left. Nowadays anyone who dares suggest that there is any rational preparation or response to a nuclear attack is laughed off the stage.
I'm sure the idea was to propagate the "better red than dead" mindset.
Yes, and generally this is done to prepare the ground (the minds of the sheeple) for sowing the seeds of unilateral disarmament, or a "nuclear freeze", or other such idealistic and naive notion. Fortunately for us and all nations who believe in individual liberty and free societies, our leaders during the period of roughly 1948-1960 were made of sterner stuff. The flower power and disco decades eroded that badly. Reagan tried to reverse the trend but the Clintonites revived it and a general feminization of America took place. The result was 9/11. The next sucker punch might be worse.