It's not that multiprocessing systems didn't exist at the time Hopper delivered this lecture; it's that they remained fairly niche products for computing resear

It's not that multiprocessing systems didn't exist at the time Hopper delivered this lecture; it's that they remained fairly niche products for computing researchers and fairly deep-pocketed organizations. At the time, multiprocessing was still very difficult to pull off. It wasn't necessarily analogous to just yoking two oxen to the same cart. It was maybe more like a world where the time it takes to breed an ox that's twice as strong is comparable to the time it takes to develop a working yoke for state-of-the-art oxen, and also nobody's quite sure how to drive a two-oxen team because it's still such a new idea. So the parallel option wasn't as sure of a bet from a business perspective as it is now.