I think it's convoluted way to describe it. Very technically-practical. I agree it's probably because of historical context.

The argument I read out of it is that using goto breaks you being able to read and follow the code logic/run-logic. Which I agree with.

Functions are similar jumps, but with the inclusion of a call stack, you can traverse and follow them.

I think we could add a goto stack / include goto jumps in the call stack though? It's not named though, so the stack is an index you only understand when you look at the code lines and match goto targets.

I disagree with unit tests replacing readability. Being able to read and follow code is central to maintainability, to readability and debug-ability. Those are still central to development and maintenance even if you make use of unit tests.

Perhaps it’s because at that time people would be running the programs in their heads before submitting them for processing, so they tended to use more of a computer scientist mindset - whereas now we’re more likely to use test cases to convince ourselves that code is correct.

This is 1968. You didn't have an IDE or debugger. Your editor was likely pretty terrible too (if you had one). You may have still been using punch cards. It's possible the only output you got from your program was printed on green-bar paper.

"Back in the day" it wasn't uncommon to sit with a printout of your code and manually walk though it keeping state with a pencil. Being able to keep track of things in your head was very important.

GOTO existed in part for performance purposes. When your CPU clock is measured in megahertz, your RAM is measured in kilobytes and your compilers don't do function in-lining it's quicker and cheaper to just move the program pointer than it is to push a bunch of variables on a stack and jump to another location, then pop things off the stack when you're done (especially if you're calling your function inside a loop). Even when I was programming back in the '80s there was a sense that "function calls can be expensive". It wasn't uncommon then to manually un-roll loops or in-line code. Compilers are much more sophisticated today and CPUs are so much faster that 99% of the time you don't need to think about now.

Oddly enough the arguments against GOTO are less important today as we have much better development tools available to us. Though I certainly won't recommend it over better flow-control structures.