Just about every vehicle ever made has more braking force in the front, as that's where there's *usually* more weight, and, more importantly, where the weight is transferred during braking. Mid- and rear-engined cars are usually more even front/rear, as they have more weight in the back (obviously)
As for the rears wearing out faster, it's POSSIBLE that ESP is causing that- if you're trying too hard to drive it like a sports car and not turning ESP off, and it's scrubbing your speed at the rear tires using brakes as well as the ignition cut. I rarely use my ESP (I run with it turned down 99% of the time), and my rear pads are wearing less than my fronts.
Was the Jeep bought used? Maybe your fronts were replaced before? You gave precious little info (mileage, etc.), so it's hard to gauge. Were the rear pads worn evenly? Pics would be lovely