I work as an inspector on these street stalls that sell fruit and veg, and one guy was still selling his fruit in pounds and ounces. “You do realise you have to go metric now” I said. He nodded “Look I’ll overlook it but you have to get these in kilos and grams by the next time time I come round” He nodded again. I thought I was being reasonable don’t you?
And lo and behold by the time I’d come round again a month later, he still hadn’t bothered to change
Which just proves it. You give them 2.54cm, they’ll take 0.914m