Mils are a terrible compromise. On the one hand, they acknowledge that dividing by 1000 is useful and that it's easier to work on a linear scale instead of mixed units and fractions. On the other hand, it stubbornly clings onto the inch instead of embracing the millimetre or micrometre.

As a side note, I heard of carpenters who work in decimal feet. Yeah, that's great, adding yet another option to the mix. Everyone else talks in feet and inches.