> Was it just a product of time?

Same reason that nobody did the Fosbury Flop at the 1948 Olympics - Dick Fosbury hasn't shown this technique yet and it's not obvious if you've never seen it that this is a better way to perform an Olympic regulation high jump. Twenty years later, he does exactly that and wins Gold and by the 1988 Olympics this is how everybody does a high jump, but in 1948 nobody knows it.

Your instinct to "create a separate function" is exactly Structured Programming.