Not flute working but sewing, and I know it sounds insane, but mm is just to small to be practical. It's one or two strands of tread whereas 1/4 or even 1/8 gives a proper piece to cut of.

And 1/4 inch seem allowance is just so much less bulky than the standard 0,75 cm, and so much more intuitive for me to work with .... and f. I just realized that all my arguments for using inches are based on habits..

Even though I'm european I never really applied cm in anything but homework and therefore never got a real sense of it. And a lot of the nice sewing patterns are in inches so that's where i started.