The direct quote: "The most important single decision I ever made was to change the IBM 360 series from a 6-bit byte to an 8-bit byte, thereby enabling the use of lowercase letters. That change propagated everywhere."

www.wired.com/2010/07/ff-fred-…
/via en.wikipedia.org/wiki/Fred_Bro…

and I found it referenced again
/via www.infoq.com/news/2022/12/fre…