Earlier quoted context omitted.
How wasteful, ed uses just ? for all errors, a 3x saving
Ed also uses "?" for "Are you sure?" If you're sure, you can type the last command a second time to confirm. The story goes that ed was designed for running over a slow remote connection where output was printed on paper, and the keyboard required very firm presses to generate a signal. Whether this is true or folklore, it would explain a lot. GNU Ed actually has optional error messages for humans, because why not.
When each line of code was it's own punch card having a { stand alone on a line was somewhere between stupid and pointless. Also explains the reason why lisps were so hated for so long.
By the same token today you can tell which projects use an IDE as the only way to code them because of the terrible documentation. It is after all not the end of the world to have to read a small function when you can just tab to see it. Which is true enough until you end up having those small functions calling other small functions and you're in a stack 30 deep trying to figure out where the option you passed at the top went.