dddd

I've always thought that the length of the fork legs was enough of a strength-to-weight issue for there to be a bias toward using as short of a front brake reach as practical.
So when using fork tubes, crowns and steerers having standard strength levels, cutting the fork legs shorter improves fork durability (and improves stiffness to the second power of leg length).
So lengthening the fork leg tubes decreases the strength and increases the weight of a fork. It also makes it more flexible in all directions, including torsion.

I also note that rear brakes almost always have relatively poor modulation due to the combined (multiplied, actually) detriments of more cable friction and greater cable elasticity. So a lockup at the rear wheel is not so quickly remedied by the rider's reaction of releasing the lever.
Now it is also true that decreasing the leverage between the lever and the rear brake pads only increases the needed cable tension and thus the elastic stretching of the cable, which seems to at least somewhat offset the above theoretical consideration.

It's not unusual to find modern disc-braked bikes having a larger rotor on the front wheel (never the other way around).
Motorcycles too, to an even much greater degree, and it is at least as much about power than about heat buildup.