From what i can remember from 1st grade: the logic is the other systems were used by those who didn't want the US to be independent from the British. So to make a point the us didnt want to use those systems.
Fast forward ten years to 2000s, that way of think as died. But it's too late. Imperial system is deeply engrained into the US usage. I hate i have to use metric at my job. Never was i taught metric in any point during grade school days.
I will stick with imperial out side of work. Especially for cooking and baking. Metric system is a mess and doesn't make sense to me. Thank god for the convertgent charts at work