I wouldn't be surprised if this was done back when things were coded on punch cards and submitted for overnight processing. Iteration then was very time expensive so it would have made sense to check and re-check as much up front as possible.
My father (who graduated with a BS in EE in 1970), said he was only allowed one hour of computer time a week, so the students did everything by hand, including scouring for bugs, before they got near a keyboard.
