It's not so crazy when you consider the specs of the machines Unix was developed on. A PDP-11/20 comes with 24k of memory (16k 18bit words) and 500k of drive space and was shared between an entire department full of people.
The reason Unix exists is because they couldn't afford a machine big enough to run Multics.
The reason Unix exists is because they couldn't afford a machine big enough to run Multics.