Well, this is largely a US centric site....and in the US we don't commonly use the metric system, so, it shouldn't come as a surprise for us to use non-metric measurements in non-scientific situtations.
For instance, I would have no idea in my head without looking it up, as to how to dress if the weatherman on morning TV said it would be 20C outside....but if he said 20F outside, I'd know to bundle up as that it was really really cold out.
The US isn't likely to change anytime in the near future, so, no need to get on a soapbox, and try to sound sophisticated and holier than thou about it all.
And I do believe the US aren't the only ones to still use non-metric measurements, I even understand that in some EU countries they occasionally still use imperial units of measurements for some common every day things....pints of beer, etc?