I feel dumber having read that.
Banning a whole country because you disliked a company?
Dealing with stuff that’s ‘almost working’ is often harder than starting from scratch; ask any tradesperson.
They also apparently cannot get their heads around the fact that people might give you a discount if you advertise their brand. Ad-supported pricing has been around for a long time; it’s not some voodoo.
Converting between Kelvin and Celsius is simple addition; converting between Rankine and Fahrenheit is simple addition. Converting between the two groups requires multiplication, and pre calculator, that’s notably harder.
Also, all your kJ/kg/°C or BTU/lb/°F tables and factors are identical when you swap to referencing absolute zero. If you change to the other unit system, all that goes out the window.