Why do newspapers use multiple columns?

I am amazed that not one of the responses gave the ACTUAL reason which is that it is far easier to work with shorter line lengths when it comes to the type set. This is especially true with the Linotype machine which revolutionized the newspaper industry. These devices actually formed the type set plates as they went along, line by line, creating molds that would be used to form the type. Much easier to make molds that were no greater than 2 inches worth of characters. And before that when laying out the type set was done by hand, it would be much easier to work with smaller lines at once.