The focus of it is what you are used to.
All scales are basically created equal - they must be, since they measure the same thing and scale the same way. (No pun intended.)
The only difference there can ever be between C/K/F (or R for that matter) is multiplying by one constant and/or adding another.

Yanks use Fahrenheit, grow up with it, and see it used every day. Therefore it is intuitive and logical. To them.
The vast majority of people on Earth - about 95% - actually don't, so it isn't.

That makes the phrasing and underlying assumption pretty characteristically American, and tempting to poke some gentle fun at.