What was going through their minds in the 60s when they amassed 5,000...10,000 but went on to amass over 30,000? Was there any point after a few thousand?
Back in the day, most of these weapons were to be dropped from massed strategic bombers or launched on short range missiles. You needed lots both because a lot of these were never going to make it to the target and those that did would be highly inaccurate. This is combined with most of the nukes being intended to either take out the adversary's large stockpile, or survive the use of the adversary's stockpile.
Then there's the crazy use cases where they made nuclear weapons fitted for air-to-air missiles carried by interceptors as well as ground based air defense. The motivator being the poor accuracy of missiles at the time as well as why shoot N missiles at N incoming bombers when you can fire 1 and take out a whole formation. There must have been hundreds of warheads produced for those purposes alone.
Keep in mind that Sputnik only happened in 1957, so the chances of a nuke actually hitting its target were much smaller during the build up than after the rollout of ICBMs. A lot of these were tactical nuclear weapons deployed in Europe to be launched at invading Soviet forces (including by infantry! Look up the Davy Crockett if you want to see Fallout's mini-nuke's real life counterpart)
