Um, ACU is a result of British Imperial.

Brits still use Imperial in day-to-day conversations.

Metric is still largely bound by human scale - Celsius is bound to water at earth pressures and temps. Meter is bound to earth circumference:

one ten-millionth of the length of a quadrant of the meridian

Today it's defined as:

the distance light travels, in a vacuum, in 1/299,792,458 seconds

Utter arbitrary nonsense to continue to use the yard and calling it by a different name.

This whole meme is a joke fueled by hubris. At least Kelvin is tied to a universal constant.

(I use both ACU and metric every day, they're simply different).