That is how I learned cursive. Trying to write one line hundreds of times, the only efficient way is cursive.
Teachers also felt like that wasn't in the spirit of the punishment so it had the added fun of sticking it to "the man!"
You basically used Taylor-esque division of labor with yourself. Doing the same task a lot usually you become faster and more efficient at it. If you only have yourself it still might be faster if the task is repetitive enough and your context switching time is less than the time you save by writing one word so many times.
Still yet to tackle that one (after I learn ambidextrousness).
(Said as someone whose hand-eye coordination could do with some serious tuning)