The reason why ships use knots lies back in the Mercator projection where one easily measure distances in minutes/degrees on the N-S axis, and a knot is 1 NM/hr (~minutes/hr). But aviation uses land miles, not nautical miles. I always feel it’s stupid when flying and hearing the altitudes in feet. As if anyone was at ease with that unit to measure altitudes, even Americans.
But OK, I got it that wind barbs are traditionally in knots. I had some disciplines of Meteorology in my long time Geophysics degree and still remember those basics of atmospheric circulation and why you guys at the low under spin in the oposite sense. The difference between barb and grdbarb is not nice though.
(my GMT.jl ecmwf() function is almost ready for prime time)