Disclaimer: I am European living in Canada and I wish metric system to be the only system everywhere and hate to use imperial system.
Having said that I have to recognize that it is a matter of habit. I am pretty sure there are people for whom metric system looks stupid.
There is a logic behind imperial system. In it, units are duodecimal (base-12) as opposed to decimal units of metric system. The rationale for that is that 12 is divisible by 2, 3, 4, and 6, whereas 10 is divisible only by 2 and 5. Apparently dividing things into 3 and 4 parts was very important when people were not educated enough to understand the concept of fractional numbers. Babylonian numerals were base-60, there are still special names for numbers 11 and 12 in many languages, and day is split into 24 (12*2) hours and hour is 60 minutes and minute is 60 seconds.