This sounds snarky but I don't mean it as such. It's what was available and how much knowledge was passed around. It wasn't hard to learn about even esoteric things if you had a good library. It was hard to find more than one such book though, so there wasn't as much opportunity for expansion of knowledge by comparing approaches.
I like the internet age better though it has become more challenging to separate fact and fiction. The library didn't have too many fake science books.