Bearings were developed in Europe and have always been officially metric. The maths behind engineering is far easier if you use SI units. The leftover imperial components are related to tubing sizes, and everyone refers to them in metric anyway (eg 27.2mm posts).
I don't trust someone who refers to axle sizes in imperial to understand anything about component design beyond aesthetics.
Bearings were developed in Europe and have always been officially metric. The maths behind engineering is far easier if you use SI units. The leftover imperial components are related to tubing sizes, and everyone refers to them in metric anyway (eg 27.2mm posts).
I don't trust someone who refers to axle sizes in imperial to understand anything about component design beyond aesthetics.