Why use metric? Because the fact that 1440KiB is 1.41MiB is annoying.

It doesn't make it better, it's just really much more convenient when you're working in a base 10 digit system. There are lots of times when the advantages of an alternative unit system outweighs that convenience.

Its a funny thing that so many people are emotionally attached to unit systems. It's a tool, use the best one for the job.