Imperial units are good because they're based on subdivisions and commonly referenced lengths that people actually want to make. You want to divide length up into 12 equal parts, because 12 is divisible by 2,3,4, and 6. Dividing it up into 10 equal parts kinda sucks, because 10 is only divisible by 2 and 5.
When measurement scales are important, we ditch metric (or modify it). For example, computers don't use the usual metric units - a Kilobyte is 1024 bytes. This is because you actually want to divide things up by powers of 2 when you're working in binary.