Because an American will say they are 2/9ths of a foot across,
and
the rest of the world will go W T F? How many centimetres is that?
And the American will go..."You and your nancy socialist metric [bleep]. Real men measure in strange fractions of an olde english measurement. We won the revolution dammit! But we kept their archaic measurement system."
You're not wrong...
I'm used to both systems, since I've spent my career in manufacturing. I much prefer metric these days for everything except temperature. I do prefer our scale there because of the smaller increments, even if the scale itself is bizarre.
