The use of the X symbol to mean "cancel, close" isn't nearly so mysterious as the author claims. "Cross off" and "cross out" are common phrases in English, and

The use of the X symbol to mean "cancel, close" isn't nearly so mysterious as the author claims. "Cross off" and "cross out" are common phrases in English, and traditionally denoted by an X symbol (the "cross"). There is no reason to suppose that the GUI usage was inspired in any way by exotic Japan. The X as "cancel symbol" has been quite common in the west and indeed worldwide for millenia.