You lot came up with them, Graham.
Yeah, we use those too, and feel free to spel it however you'd like.
C'mon, that's like saying "stuff sounds more expensive in .au because your dollars are smaller". Meaningless. It's all in what the current unit of (measure) for (thing) is.
Why force anything? Important stuff (medical, other scientific, much food) is done with metric measurements. The social inertia, and the tooling costs to change, aren't trivial, and the "cost" of it being the way it is, is trivial.
Where do you people come up with this stuff? What does the US government have to do with the fact that TRX was a lousy standard in the first place? Oh, and what exactly is 185/65 if not metric? Oh, wait, the 15. BFD. At least we've got something descriptive, rather than "H-78-15" which was an old standard. Again, who cares if it's in inches, centimeters, furlongs per kumquat, or something else? More to the point, why care what a different country does?
Our culture isn't such that the governemnt can "force" us to change our measurement system, it just doesn't work that way. Important stuff is done in metric, but cookbooks will be in cups, tablespoons, and teaspoons for a long long time.