The US converts from metric for their imperial units, and has done for decades. Not sure about the others.The imperial system is far from dumb. The units actually have meaning behind them. It's not defined as a random fraction of something very intangible by some organization in a foreign country that may not exist in 50 years. Using metric is a testament to the lack of sovereignity of a country.
What meaning do they have? I would not be surprised if more than 90% of the population has never seen a barleycorn (three of them to an inch you know), and a foot was variable between towns and cities for many centuries before people decided that was a stupid idea, some even tried to base it on various monarchs.