The UK still uses imperial for things. For example, the UK buys gasoline in liters but measures the efficiency of the cars by miles per gallon. They also use miles to measure distance for driving. They measure people's weights by stone but only one of the various stone measurements.
Personally, I don't think the UK has any room to make fun of anyone using imperial units.
The old BSW system was wild. A 1/2" wrench measured the width of the thread, not the head of the bolt. So BSW wrenchs are way larger than the similarly marked SAE wrench.
That makes no sense. It would (only a little) if it was the other way around, since 0C and 100C are based on water, and F is "easier" to relate in how one feels hot or cold (I know that's totally subjective).