I've realized that the display size, in inches, is sometimes in the name or model number of electronics that are sold not just in the US. Do people outside the US also talk about buying 55-inch TVs, 14-inch laptops, and 27-inch monitors? Does it naturally roll off the tongue or does it seem strange to anyone?
If it's all inches, why didn't measuring screens in centimeters take off?
feet for vertical distances -- such as 1000 ft overhead separation for aircraft heading towards each other
meters for horizontal distances, such as 1.3 km between two aircraft going for landings on separate, parallel runways of the same airport
statute miles for visibility ahead of the aircraft, such as when fog is ahead
nautical miles for distances to waypoints and navigational aids
The bizarre thing is that these are all conventions that stemmed from good rationale, at least initially. Using meters for horizontal distances means it's hard to confuse it with vertical distance, when speaking over rough radio comms. Statute miles is what the meteorological agency in the USA would report, and ATC provides that information to pilots. And nautical miles, as the name suggests, has a rich seafaring tradition, which aviation adopted wholesale.
It's why aircraft have the red (left) and green (right) navigational lights, same as ships do. It's also why the "rule of the road" for two intersecting aircraft is for the right-hand aircraft to go first, since their pilot sees the other's green light, while showing a red light to the halting aircraft.
TL;DR: everything boils down to: "it's how we've always done it"