I never understood the anti-metric thing. It's a few minutes to learn that there's about two pounds in a kilo and the better part of two pints in a litre. Job done, you've learned a set of simple and easy-to-use units, rather than cubic bloody hogsheads per furlong.
It's almost like they're the province of the really fucking stupid.
Because of my parents I grew up using imperial at home, and metric at school, and then to the exasperation of the woodwork workshop technician, the two together*.
I still find it easier to say "it's 200 yards" for when giving rough distances such as in directions "How far's the pub?" "couple hundred yards!". When a Dutch friend asked wtf a yard is, I just said it's a small meter.
I went full metric when I worked at ESA, Mars polar orbiter taught me the importance.
My main bugbear tho is that the metric terms are more of a mouthful. "1 mile" vs "1 keel oh meet er", tho some pronounce it "clometer". "Ten k" is a bit easier to say. But 6 inches is still easier to say than 150 mil...
I tend to use the engineering subset of SI units, km, m, mm, µm, I find it offers a certain level of error checking to what you've written down. If you are cutting wood for a shelf and it's marked as 1m x 200{m x 10|m, and the bit in front of the m has been smudged out, or it's a noisy phone line, you can infer a certain to a certain amount what was intended. 1m x 20m seems a bit big for a shelf, 1m x 200cm could work, but then that's still a weird shape for a shelf... 1m x 200mm that seems about right for a shelf, so next up thickness. 10µm seems... complicated in wood... so maybe 10mm, bingo 1m x 200mm x 10mm, that looks like sensible size for a shelf. Built in error checking...
J
*For a project I sent in a cutting list that included one part that was 3" x 10cm x 12mm...