alt Hacker NewsDon't want to particularly wade into an aspect ratio discussion, but the common thought around the standardization of 16:9 in home cinema/HDTV was due to the aspect ratio of human vision being somewhat of that ratio, due to use having two horizontally-spaced eyes.
wikipedia has the history of 16:9 - it originated as a compromise of the other popular aspect ratios at the time: https://en.wikipedia.org/wiki/16:9_aspect_ratio#History