Discovering something new is what most of us would like to achieve especially if we know that it has the potential to grow.
If they somehow realize it and they continue to further develop it then there is a big possibility that they were the founder of the current blockchain right now.
The idea of decentralization is nothing new. And you are right, they didn't realize how close they had gotten to the working principles of Blockchain tech.
I guess, legacy hardware, inadequate research and a proper need was not yet realized. This was right around the time when Nixon shock was taking its effect and USD had just started to lose its value when compared to gold. People hadn't yet lost their hopes on the US currency. So there was no compelling need for an alternative currency system back then.