The converse is not true, however. My wife buys many of her perfume-making supplies from foreign suppliers; she has to do all her purchasing in metric. Fortunately, most of that industry is converting to metric, so most of her "recipes" use grams and milliliters...
I have been both English and metric since majoring in physics a few decades ago. I think that tsunami tidal waves should be measured strictly in feet and stellar distances in parsecs. That is my considered opinion and about as far as it goes.