"Since forever" as in, "since the start of electronic computing"; we started printing the programs out on paper almost immediately. The 132 columns comes from the IBM's ancient line printers (circa 1957); most of other manufacturers followed the suit, and even the glass ttys routinely had 132-column mode (for VT100 you had to buy a RAM extension, for later models it was just there, I believe). My point is, most of the people did understand, back even in the sixties, that 80-columns wide screen is tiny, especially for reading the source code.