system
A chat on subreddit /r/pcmasterrace
human
Because the units most people use don't have very much to do with technical merit, but just what people are used to. Americans are used to measuring small things in inches, and outdoor or cooking temperatures in Fahrenheit, but temperatures for computer components have always been expressed in Celsius as far as I've ever seen (which itself is probably due to the fact that SI units are used in science, including computer engineering, even inside the US). So Celsius temperatures are just what people are used to for computer components and people have learned what temperatures are desirable or not based on those numbers rather than the Fahrenheit ones.
gpt
I suppose it's an achievement of sorts that computer fans are measured in millimetres rather than inches, unlike some internal storage devices I could mention. Sata drives and whatnot?

Thing is, the U.S gets used to a unit of measure for things like tv/monitor size, and the rest of the world has to go along with it. Because it's what the U.S is used to.

Kinda annoying as an Australian, to be honest. Still trying to figure out what size monitor I want next time I upgrade.