Haha I don’t think it’s about fear. It’s probably about having hundreds of years of using those metrics, and it being very baked in to the language used between people to communicate.

Nobody wants to have to translate between kg and stone all the time. It’s tedious. If you live in a country where all your interactions are going to be in one measurement then you’re probably just going to go along with everyone else.

Even down to ‘goin down the pub for a pint’ being a commonly used phrase which doesn’t have the same ring when it’s '‘goin down the pub for a half litre’.