[Feynman] and other Manhattan project physicists were present at the creation. They had to use crude early contraptions for mechanical calculation in bomb design computations. Thus, the habit of reducing a complex problem (whether in physics or machine learning) to primitive operations was second nature. Already for kids of my generation it was not second nature – we grew up with early “home computers” like the Apple II and Commodore, so there was a black box magic aspect already to programming in high level languages. Machine language was useful for speeding up video games, but not everyone learned it. The problem is even worse today: children first encounter computers as phones or tablets that already seem like magic. The highly advanced nature of these devices discourages them from trying to grasp the underlying first principles.
If I am not mistaken the t-shirt he is wearing is from the startup Thinking Machines, which built early parallel supercomputers.
Just three years later he was gone. The finely tuned neural connections in his brain – which allowed him to reason with such acuity and communicate with such clarity still in 1985 – were lost forever.