Imperial revolves around 12's I'm sure, and if you think about it, 12 is actually a very useful number:
10 only has a few factors; 1, 2, 5, 10
Whereas 12 has; 1, 2, 3, 4, 6, 12
This makes calculations much easier. In our system, division by four and three is more awkward than it is with 12. 10/4 is 2.5, 12/4 is 3. 10/3 is 0.3333333rec, 12/3 is 4. You see where I'm going with this? Back when it was developed, 12s made sense because of how easy it was to manipulate.
There may be other factors too, but as far as I'm aware the fact that 12 is a nicer number to deal with was an influence. In fact, I'm sure there is a group centered around trying to move us all to a base 12 system simply because it would simplify a lot of things - but that's almost a different topic. What I know on the subject is above :)