Anyone have pics of the front/rear pads next to each other? I know on my previous cars and my wife's Camry, the rear pads are usually thinner too. There'd be no logical reason for having more brake bias at the rear unless more of the weight is at the rear. In a perfect world (more so for racing purposes) you'd want the front/rear bias to be "equal", and by this I mean the ratio of brakes-to-weight, so if you have a perfect 50/50 split as far as weight front-to-rear, then you'd want the same braking force front-to-rear. But say a 60/40 split, you'd want 50% more brake torque on the front tires. With our trucks having a larger rear rotor though that tends to effect brake bias a bit so that could be why also, higher center of gravity effects it, less weight on rear axle, there are a ton of factors involved in brakes that it's not even funny lol. A rear-biased vehicle will be squirrely and not that much fun to drive. I'll quote a great brake article that I've had for years:

"As braking force is continuously increased, one end of the car must eventually break traction. If the front wheels lock up and turn into little piles of molten rubber first we say that the car is “front biased”, as the front tires are the limiting factor for deceleration. In the not-so-desirable situation where the rear tires are the first to lock we say that the car is “rear biased”, but the driver would probably have a few more choice adjectives to add. In either case, however, one end of the car has given up before the other, limiting the ultimate deceleration capability of the car.

Just like the car that pushes its way through corners all day long, a car which is heavily front biased will be slow and frustrating, but relatively easy and benign to drive. On the other hand, like the oversteer monster that people are afraid to even drive around the paddock, a car which is severely rear biased will be a scary, twitchy ride resulting in a bad case of the white-knuckle syndrome. Envision an imaginary co-pilot yanking up on the park brake handle in the middle of every corner, and you begin to get the idea. While a rush to drive at speed, it will be horribly slow on the stopwatch."