... For the reason that IBM made their 1928 card with 80 columns, in an attempt to increase the storage efficiency of Hollerith’s 45-column card without increasing its size?

That said, ~60 characters per printed line has been the typographer’s recommendation for much longer. Which is why typographers dislike Times and derivatives when used on normal-sized single-column pages, as that typeface was made to squeeze more characters into narrow newspaper columns (it’s in the name).

The fact that the claim is wrong on multiple levels (IBM punchcards, VT100 did 132 columns as well) is part of the fun.