That's a question which still needs a legitimate answer.
As far as I can tell, it had something to do with percieved recoil, magazine capacity, DA vs. SA, a "learning curve", and the usual assortment of under-dealings associated with awarding gov't contracts.
I own (and sometimes carry) a Kimber Custom Shop Pro Elite wich is their version of a highly customized Combat Commander. It's a good gun, and fun to shoot.
The differences between it and my HKP7 are many, but both have their own unique advantages.